What is an isolation coat?
An isolation coat is a coat between your finished painting and the varnish.
It is transparent and creates a physical separation between the varnish and your painting.
This is key because otherwise the varnish will stick to your painting and be a nightmare to try and remove. The varnish is not permanent, it just acts as a dust collector that you can remove and replace, every 5 to 10 years depending on how dusty the environment your painting is kept in.
To make an isolation coat I use GOLDEN Soft gel gloss. This medium is off the hook, and I highly recommend you buy it along with an Acrylic Glazing Liquid Gloss if you are starting acrylic painting. These bad boys are all you need.
Alternatively, Golden has recently released a pre-mixed isolation coat you can use.
A full-gloss finish can do amazing things to your paintings…
Step 1: How to apply an isolation coat to an Acrylic painting
Checklist before applying an isolation coat:
- Make sure the painting is 100% dry, ideally leave at least 24hrs before applying an isolation coat.
- Look over the surface of the painting up close to see you don’t have any rogue brush hairs on the surface.
- Photograph your painting. It is soooooo much easier to photograph a surface with a matte finish. The gloss of the isolation coat will reflect everything and if you can’t turn off the flash on your camera, the light from the flash will bounce off the reflective surface.
- Sign your work, a signature under gloss just looks lovely.
- Use a clean brush and then only use this brush for varnish, it will be tempting if you are in a rush to use another brush that you ‘think’ is completely clean. I’ve done it before and the polyurethane loosened off dried on acrylic paint and went over the painting, not a good idea.
- Find a clean jar, same reason as the brush, clean is good for isolation coat or varnish.
- A flat, dust-free area. You need to be able to leave the painting in this position for an hour or two
Pro tip: If you are coating the sides of canvas you can slightly raise each corner with a small piece of wood so the painting doesn’t stick to the surface below.
Pro tip: If you want a matte finish and have used an absorbent ground (such as ground for pastels) it is important to add an isolation coat. Even though it seems counter-intuitive to put a gloss isolation coat down first then put another matte varnish coat on top. If you left it without the isolation coat the matting agent in the varnish would remain on the surface, the solvent would be absorbed into the ground resulting in a white residue.
Step 2: How to mix your isolation coat
You’ll only have to mix an isolation coat if you’re using soft gel gloss, the pre-mixed isolation coat is ready to go straight from the pot.
1. Mix two parts soft gel gloss to one part water (ideally distilled)- Mix more than you think you will need, trying to match the exact consistency if you run out is not fun!
2. Add the water – little by little as it will mix in better.
3. Do not be tempted to add more water
4. Re-read point 3 – the mixture will appear too thick, too white, and just a little scary, it isn’t.
5. Get a clean, wide brush – I usually use a 2-inch flat nylon brush, you can use a ‘varnish’ brush, but it is not essential. I wouldn’t recommend a decorators brush as it will show too many brush marks, you want a brush that is smooth to the touch so you can just glide it over the surface.
6. Lay your work on a board -I use a piece of MDF, or newspaper, you are bound to get some overspray and/or drips.
7. You need to work quick – paint the soft gel gloss over your painting in all directions to make sure you don’t miss a bit. (Don’t be tempted to go over semi-dry areas as it can easily pull up the isolation coat.)
8. Work side to side, left to right, slightly overlapping each stroke – you are aiming to have no visible brush-marks
9. Squeeze out excess soft gel gloss from your brush so it is practically dry, smoothing out any raised areas of soft gel gloss.
10. Gently brush over the surface – check the sides for any overruns, get down to eye level with the painting and look at the reflection at an angle, this helps you to see if you have missed any bits.
11. Leave to dry
12. Admire
An uneven finish to a painting, some parts matte, others gloss can be very off-putting to the viewer.
A unified finish both enhances the colours and it can be a great way to add a professional finish to your paintings to add dollars to the sale price.
One final thought if you’ve never applied an isolation coat before.
Making a Test Varnish
If you’ve never used an isolation coat (or applied a varnish) your best investment to achieve a good result is to practice.
Just don’t practice on a painting you’ve been working on for weeks.
Make a few small test pieces (6 x 4 inch) and paint them with a range of solid colours.
The test pieces can be made on thick card or scrap canvas, make sure you have one that is dark, preferably black so you can see how a matte or glossy finish alters the final finish.
Then you can try a variety of brush applications and different finishes of varnish until you find the perfect combination for the aesthetic you’re after.
Pro tip: If you’re not sure if your painting is finished, or you are nervous about varnishing it, you can leave an isolation coat on for ages, and then repaint on top in the future. Just bear in mind the surface will be super slippy and won’t soak up moisture (see: How to paint over an acrylic painting) so paint thick!
You might also like:
1. How to apply a varnish to an Acrylic Painting
2. Why some artists Varnish their work (And others don’t)
3. 7 Questions you need to ask yourself before Varnishing an Oil Painting
Resources:
Golden 236ml Soft Gel Gloss
Hello Will,
Thanks for all the information on the isolation coat and for all the follow-up comments I get in my email.
I have another question: Do I have to put a varnish on after the isolation coat or can I just leave it at that. Great site and great information.
Cheers
Edwina
Hi Edwina, personally I would always add a varnish coat so the in the future if you ever needed the surface cleaning you would just remove and reapply the varnish coat, with the isolation coat acting as a barrier to the paint surface.
Cheers,
Will
Thanks Will for the quick response.
Edwina
My pleasure Edwina.
Will
Hi Will, I want to apply an isolation coat to a 10′ x 5′ mural and would like to know how much mixture of Golden soft gel gloss and water will be needed? Do you have insight into how much I might need? I will apply by brush.
Thanks!
Holy Moly, Mary Ellen that’s quite a painting! I’m not sure the exact amount per square foot/metre Golden recommend, you could try the Golden technical support as they should be able to give you a good idea: https://www.goldenpaints.com/contact_us
Cheers,
Will
Hi Will,
Have always avoided acrylics, using watercolours and pastels, but your brilliant website has given me confidence to try this medium. Many thanks for your generosity! I have completed two seascapes on canvas which I want to hang in the bathroom. I am high up in Scotland and near the sea, so it is damp anyway, and of course they will live in a steamy atmosphere. I made a trial painting on acrylic paper and did an isolation coat with Jackson’s gel medium, which I already had, it looks fine, and I have some Pebeo spray varnish to apply later.
My question is that as the pictures will hang in a damp atmosphere would it be advisable to apply an isolation coat and the varnish on the back on the canvas as well, to protect them?
TIA
Hi Lesley, pleased you’ve been enjoying the lesson. If the painting is ideally framed and the back of the frame sealed with board and tape it will help to protect the painting against humidity. If you’re hanging bare canvas it won’t do the canvas any harm to apply an isolation coat, but you could also tack some thin board onto the back to help prevent moisture getting behind the surface.
Hope this helps,
Cheers,
Will
Thank you so much for your reply, Will. The paintings are done on box canvasses, with quite deep sides, and I intend to hang them without a frame, so I didn’t really want to nail any wood onto the back. I thought that maybe the isolation coat plus the coat of varnish on both the back and the front of the picture would protect it against damp or mould. Or am I being naive? I’d monitor the pictures and wipe them down regularly. I just wondered if there was something wrong in covering both sides of the canvas with mediums.
Thanks again
Hi Lesley, if you didn’t want to attach anything to the back of the canvas you could use a piece of foam board cut to size and gently push it into the back. if it’s a tight fit it will stay in position without needing to glue/or attach it to the actual stretcher bars.
Will
That’s a good idea, Will, I will do that. Should I still add an isolation coat and varnish to the back of the canvas, or will that not be necessay if I use the foam?
Many thanks for your time :-)
Hi Lesley, I wouldn’t think you’d need to add the isolation coat on the back if you have the foam board backing.
Will
OK, thanks again for your advice, it is much appreciated :-)
Hi! I’m glad I found your site with info on isolation coats and varnish! I painted some acrylic paintings before I found your website. I used the gloss gel directly on the paintings without diluting it. Brush marks are visible. Is this because I didn’t dilute it? Did I ruin my paintings? I don’t like brush marks, so will varnish get rid of them?
I also have done some paintings that are part acrylic paint and part Sakura Pigma Micron Pen. These have been done on canvas. While the Pigma pen is supposed to be permanent, I have found that on canvas the ink smears if it gets wet. How can I put an isolation coat or varnish on it so it doesn’t smear. I was thinking maybe I have to just spray varnish them. However, I’m concerned about how long the painting will look good if I do that (since you say varnish only looks good for 5 years).
Thank you for your help.
Hi Kim,
To answer your questions:
Brush marks are visible. Is this because I didn’t dilute it?
Yes.
Did I ruin my paintings?
No
I don’t like brush marks, so will varnish get rid of them?
Not really, unless you build up a very thick layer of varnish to the same level of the brush marks.
How can I put an isolation coat or varnish on it so it doesn’t smear? I was thinking maybe I have to just spray varnish them.
Yes, a spray varnish application would work best for this.
Cheers,
Will
Hi, amazing site. So generous of you to share all this.
My question: you mention you use a nylon brush for isolation coat and varnish?
Could you please recommend one? I have been researching and am finding it
confusing. Mottler brushes, glazing brushings ???
This is my first painting (acrylic) that I will be varnishing, and do not
want to ruin it, with a brush that might leave streaks.
thank you
Hi Addie, yes, I tend to use a nylon brush for both isolation coat and varnish layer. Many decorating brushes can work well, Wooster and Purdy are good brands. I would strongly recommend practising on a sample piece first to get the technique of a smooth flat finish.
Will
Hi Wil
thanks for taking the time to reply. I did find the answer in the comments section.
Hi Will,
I just put isolation coats on 15 paintings with two coats each. Several of them have streaks. This is not smeared paint. I was very careful about measuring the gel and water and waited 24 hours for bubbles to settle. So, I think my technique must be off. I didn’t mix the gel/water again before applying, and the consistency seemed uniform. I wondered about a couple of possibilities:
1-I assumed I should apply thinly so did not load my brush fully, but instead wiped some mixture off the brush before applying. Was the application so thin that there wasn’t enough to “level”?
2- Did wiping the brush against the side of the container introduce more bubbles? The mixture seemed to bubble the more I used it. I’m not seeing bubbles on the surface of the painting, but am trying to understand the different sheens. The effect is one of stripes, so i don’t think it is because of variation in the absorbency of different parts of the painting.
3- I started at the top of each painting and then in some cases, brushed back and forth left to right then right to left (I saw a video where someone did that), but did this change the quality of the layer? I noticed that the streaks have sort of alternating sheens, depending on from which side I look at them. Should I just be applying on one direction only?
4- I finished by removing excess mixture from the brush and then lightly went over the painting to remove any bubbles/uneven areas. The surface doesn’t not look rough, but I can see brush strokes and can tell which direction I was working in.
5- Can I fix this by improving my technique and applying a third isolation coat???
So, should I be using more mixture? Should I apply in only one direction? Why am I seeing the brush strokes at all? I did work quickly, by the way.
Thanks so much for your insights and your recommendations about how to fix!
Best,
Linda
Hi Linda, I tend to apply one isolation coat and then multiple varnishing layers if needed. You can apply the isolation coat in different directions to start with but it’s best to finish the layer in one direction so you have the same sheen to the application.
Will
Hi,
I have completed a portrait with acrylic paint but I’ve overworked the face. I’m happy with the face now but the surface of that part of the painting is lumpy and stands out from the rest of the painting. I’ve never used an acrylic medium before. If I cover the face or the whole painting with it will it even out the surface and make it look smoother? I have a gloss gel medium. If that won’t work any other suggestions? Thanks.
Hi Carina, you could build up the surface with a gloss medium but it would change the aesthetic of the paints underneath. I would try to re-create the texture on a test piece and experiment with the gloss first before committing to your portrait.
Cheers,
Will
I did a mural on a large wood chair for our town. The chair was stripped to the wood, cleaned, two coats of flat primer was put on, then two coats of flat white acrylic paint. The painting is done and I am about to seal it for outdoor use. My husband is concerned that, if I use a isolation coat, that the polyacrylic sealer won’t adhere to the surface and will not allow kids to climb on the chair without damage. Is he correct? Can I use the isolation coat and polyacrylic varnish and have it be ok?
Hi Joann, I wouldn’t like to say 100% as it’s for an external wood piece and the pieces I personally only use the method for paintings on canvas, not for hardwearing surfaces. You wouldn’t necessarily need the isolation coat for this project as an isolation coat is more for the option of removing and replacing the varnish surface in the future. I would do a test just with the polyacrylic varnish and check the finish (it can take 72 hrs until fully dried)
Hope the project goes well.
Will
Thanks, Will. I will leave off the isolation coat and see how it goes.
Joann
Good one Joann, hope it goes well.
Will
Hi Will, I just got back into acrylic painting after a couple of years of not doing much. My question is: I had some isolation coat mixed up from before. Will it still be OK? or should I mix up a fresh batch. Thanks!
Hi Deborah, I would mix up a fresh batch as sometimes, over time, a pre-mixed isolation coat can become thicker and less fluid for brush application.
Cheers,
Will
Hi Will.
First off, thanks for a superb website and some great(!) video courses, of which i’ve taken a few, which allowed me to go from not knowing what i was doing to being able to paint deliberately. I’m dorever grateful :)
I always check your guide to varnishing before i do so, and it helps me tremendously. I always wonder though, what’s the best way to clean my brush after applying an isolation coat? I get leftover plastic bits in the bottom of the brush hairs that risk getting on the canvas next time i apply.
Kindly
Tue
Hi Tue, great to hear you’ve been enjoyed the courses. I usually use a mix of master brush cleaner and a little washing up liquid, it can be a little grippy sometimes! I also find a ‘painters comb ‘can be handy, you can get them in most decorators stores and they have thin metal teeth that you pull through the brush, handy for getting to the base of the bristles.
Hope this helps,
Cheers,
Will
Hello.
I just made my first acrylic painting and confused.
If the isolation coat is just a diluted coat of varnish then why can’t you just put a undiluted coat of varnish on.
Hi Jeffrey, an isolation coat is a different substance than varnish, so when in the future if you want to remove and replace a varnish layer the isolation coat won’t be affected by the substance used to remove the varnish.
Cheers,
Will
Hi Will! I recently finished an acrylic painting and was quite proud of it, so I decided to add an isolation coat in order to varnish it with Gamvar later on. It wasn’t until I had added the varnish that I realized that the isolation coat had pulled some black paint (I had waited a full 48 hours, I swear!!) into some lighter areas. Can I paint over it, or have I ruined the painting??
Thank you so much in advance!
Hi Julia, oh no! you can remove the gamvar using gamsol and then paint over that section. In terms of repainting over the top directly with acrylics, I wouldn’t like to say 100%, you could contact the manufacturer Gamblin direct and they would know for sure. If you use a lint free cloth and gamsol the gamvar will come off and then you can touch up the paintings and re-varnish.
Cheers,
Will
Hi Will, I have been preparing canvas with golden crackle medium and liquitex course sand, along with some rice paper collage adhered with matte medium. I use acrylics for the underpaintings, and then finish with oils and RF and Shiva oil sticks. Sometimes I leave areas of the acrylic underpainting visible. How do I varnish a painting with both oil and acrylic surfaces? Thank you.
Hi Cynthia, a modern varnish such as Gamvar by Gamblin can be applied to both acrylic and oils.
Cheers,
Will
I love that there are so many comments and questions! I hope you’re still reading these. I didn’t have time to read through all of the comments, so I apologize if you’ve already answered.
My question is this: the advise on the bottle is to do a test on a practice painting first. I can do that. What I would like to know is what kind of problem could happen with discoloration? Is this rare or common? It’s my first large canvas and I’ve put a lot of work into it so far. I’d like to feel confident going in. Also, do you isolate sides (gallery wrap)?
Thanks so much,
Laura
Hi Laura, I would only isolate the sides if the sides have been painted, if not they can be left. Discolouration would happen due to UV rays onto pigments that aren’t light sensitive, varnishes usually contain UV protection to help keep the colours truer for longer.
Cheers,
Will
Will,
First time to your site and glad that I found it.
I have just finished a icon painting on canvass in acrylics and using imitation gold leaf. What gloss varnish would you recommend to go over the gold leaf and acrylics.
Hi Gabriel, I would do a test sample first as the gloss varnish can diminish some of the sheens of the gold leaf. A spray application would be the safest so it wouldn’t disturb the surface.
Cheers,
Will
Hi!
I have a question, and I am sorry if it ever was answered in all of the above comments!
I made a stupid mistake – to excuse myself I was still dizzy with the flu but had to hurry for a painting to bring to a gallery next week – anyway, long story short; as I had prepared too much isolation coat mixture, I decided to coat all the other paintings I had in waiting… and forgot I had varnished already one of them! And this painting is varnished with some parts in gloss and some in mat, as it’s the effect I wanted. Of course now it is all glossy… I wonder if I ruined my painting, as I don’t know the effect of soft gel gloss over varnish, and if not, I suppose I can revarnish it? Hoping to have an answer from you! Thanks in advance!
Hi Marie-Claude, unfortunately, because the gloss isolation coat has been painted over the matte/gloss surface it will have created one unifying gloss finish and you wouldn’t be able to remove it and still keep the previous effect of some parts gloss others part matte.
Will
Hi Will,
This is my first time using an isolation coat on my paintings. I’ve used two coats on one of my paintings and the finish is a bit uneven (some parts glossy and some matte). I plan on adding a coat of varnish that is a mixture of gloss and matte varnishes. Will the coat of varnish cover up the uneven finish of the isolation coat? Thank you in advance for your help.
Yvette
Hi Yvette, it’s hard to say 100% if it would cover and even out the sheen, usually yes, depending on how much difference there is, but you can apply a couple of thin layers of varnish which would give you an even sheen.
Hope this helps,
Cheers,
Will
Hi Will,
Thanks for all your wonderful content. I made a big oops today and applied some Liquitex gloss medium with my brush only to discover some dust particles had dried into it. They are black lint or dust flecks against a light background. Is there a method for removing these? Or do I just need to resolve to repainting these areas?
Thanks so much!
Cheers Grace, glad you’ve been finding it helpful. I can’t think of any way of removing the specks without leaving any noticeable marks. With an Exacto knife, you could probably pick out the specks but its a balance between pick out speck time and paint over time.
Will
Hi Will,
I’m so happy because I just found your site on the Internet. I’m new to painting with acrylics, and I’ve never heard of an isolation coat, and I’ve never varnished anything. I’ve recently finished a painting that I thought was worthy of saving. When the painting was wet, I loved it. Once it dried, the top part seems to have almost disappeared into the very dark background. Only from a certain angle can I still see the orange. Two questions: 1) When I varnish it, will the color come back? 2) Is that normal for a color to be “absorbed” or faded into a dark background? 3) Would you please name a particular high gloss varnish that I can buy? Thank you so much for sharing your knowledge. Betsy
Hi Betsy, the colour might come back slightly but only in saturation when using a gloss varnish. If painting in oils you’ll often get ‘sinking in’ where the paint goes matte as the oil is absorbed into the surface, it’s less common with acrylics though. Gamvar by Gamblin is a nice varnish for both Oil and acrylic.
Will
Hi Will, I’m a beginner and just finish my acrylic paint, is it fine to varnish it directly? Because it’s so hard to find isolation coat in my place.
Thanks,
Vava
Hi Vava, yes, you can varnish directly the varnish will be a permanent fixture on the painting.
Will
Hey, I love this article. I use a ton of purples which I discovered are a little less lightfast and I’ve sold some of these paintings with only 1 coat of varnish before I knew I should probably do more. Do you know if isolation coats help protect against UV? Or is that just wishful thinking on my part? Any advice?
Hey Kevin, you can get specific topcoats that add UV protection but I’d tend to rely on the UV protection from the varnish layer, the isolation coat just as a layer between the painting and the varnish.
Cheers,
Will
Hi Will!
I have just finished my first 75 square foot mural, and I am thinking, based on this article, that I should do an isolation coat. I am planning to use Liquitex Satin Varnish. What Liquitex product would be comparable to the Golden Isolation Coat? Is it ok to mix brands? Do you have any additional thoughts or recommendations for a project of this size? The mural has been painted on an indoor sheetrock surface.
Hi Lisa, Liquitex recommend using Gloss medium as a permanent isolation coat. You can also intermix brands (isolation coat from Golden, Varnish from Liquitex etc) For a project of that size I would strongly suggest trying the isolation cot and varnish on smaller pieces first to get your method down so you get the aesthetic finish you’re after first before committing to the large scale mural.
Cheers,
Will
Hi, can I use Windsor and Newton Galleria gloss medium (not gel) as an isolation coat? Thank you.
Hi Vanessa, Liquitex suggest using a Gloss Medium for their isolation coat, so in theory, yes, but I haven’t personally used it.
Will
Will I have varnished my acrylic painting without an isolation coat. Can I add it now over the varnish and then revarnish?
Hi Maggi, mmm not really, because you want the isolation coat to be the barrier layer between the painting and the removable varnish. I’m also not sure of the adhesion of the isolation coat on top of the varnish. You could ask Golden technical support, they might have more info on it.
Will
Hello, nice to meet you Will. I paint in aryl and applied soft gel gloss. What shall I do with remaining? Can I keep it or get rid of it?
Hi Kasia, if you’ve mixed up an isolation coat is a screw-top jar you can keep in for the next painting, but if the gel has been out in the air for too long it will start to harden up.
Will
Hi Will,
It’s been a long time since I’ve seen an active post here, and am not sure you’re still responding. But I’ll give it a try…I applied isolation coats (Golden soft gel) to a couple of acrylic paintings without incident (1 coat per painting). However, the latest effort, the painting that I love and was excited to gift — while applying, I went back over a spot I’d just covered (thought I was quick enough, but no) — and darn, now it looks torn up like others have posted about. And there are other areas on this painting where it looks like the isolation coat wasn’t applied uniformly, yet I used the same brush and technique as before. I’m disappointed and a bit puzzled (practice doesn’t make perfect). My question herein: what’s the rationale for not doing a second isolation coat when we “mess-up” and have the outcomes I described? I’m so tempted to give it “another go”, but don’t want to make it worse. Can you help me understand why a second coat won’t help even-out the glossiness where it’s now dull, and help smooth spots that are uneven? Again, I’m trying to hold myself back on “fixing” the issues, so the rationale will be much appreciated. BTW — I’m using all Golden products, and had planned to use Golden’s satin spray varnish.
Thanks, in advance, if you can reply.
Best, Barbara
Hi Barbara, nice to hear from you.
You can apply multiple isolation coat layers on the same painting, the only issue would be if any of the surface texture from the ‘pulled’ areas would still show through the second isolation coat layer. What you can do is grab a scrap piece of canvas and try to re-create the ‘mistake’ with the isolation coat and then practice a few layers on top to see how the effect works. That way you can be confident before trying in on your piece.
Hope this helps,
Cheers,
Will
Hi will,
I have been painting using Golden heavy body acrylics for a while and I always use an isolation coat when finished (just as is instructed above). However recently I have noticed my isolation coat is dragging/smearing my paintings and I cannot figure out why. I tried remixing my solution thinking maybe it had gone bad somehow, and I have done separate tests and learned it only seems to smear light colors. I always let my paintings dry for a few days before putting the isolation coat on, The only thing I can think of is that I use Golden extenders or retarder, But I mix that with all my colors and did not have this problem in the past. Any idea on why this could be happening?
Hi Desirae, nice to hear from you. Sounds like it could be using too much retarder with the paint mixes. If over 15% of the Golden retarder is used is can prevent the paint from fully curing dry so this might be the issue. I’d try a test just with straight acrylics and see if you get the pulling if that’s all clear think it might be the retarder.
Hope this helps,
Cheers,
Will
Hi Will, thanks for this great article. I have applied Soluvar Gloss varnish to a resin sculpture that has been painted with acrylics. However I did not realise I had to apply a gloss medium (isolation coat) before adding the Soluvar gloss varnish. My question is- can the Soluvar varnish that I have applied work as a protective layer without this gloss medium layer underneath it, or do I need to take it all off, apply the gloss medium and then apply it again? Obviously I would rather not do this! Alternatively can I add Gloss medium on top of the Soluvar varnish I have already applied and then add a final layer of soluvar varnish? I would be so very grateful for any advice. It is to be displayed in an exterior setting and my main concern is that it is protected from the elements. Many thanks, Laura
Hi Laura,
However I did not realise I had to apply a gloss medium (isolation coat) before adding the Soluvar gloss varnish.
You only have to apply an isolation coat if you intend for the varnish to be removed and replaced in the future. If you’re after more permanent varnish protection you can apply it straight to the surface
My question is- can the Soluvar varnish that I have applied work as a protective layer without this gloss medium layer underneath it,
The Soluvar will form a protective layer, the only issue would be if the subsequent varnish layers ontop use the same varnish removal solvent, so if the varnish was every removed in the future it could damage to paint layers.
Hope this helps,
Cheers,
Will
Having finished my first ever acrylic painting on canvas, I am ready to varnish it, but also concerned as I have never used an isolation coat before. I purchased “Golden Isolation coat” …. My question is do I need to thin this product before use (as it is not a gel, but quite a thin liquid …. resembling milk in texture). I will appreciate any advice on this matter.
Hi Peter, the Golden isolation coat has been created as a ‘ready to use’ brushable isolation coat, so you’re good to go!
Cheers,
Will
I’m sorry if you’ve already addressed this but is it safe to do a thin coat and then the next day do another thin coat on top of that? Thanks for your article!! So helpful
Sure thing MacKenzie, that would be fine.
Will
Hey this was very helpful! I painted my skateboard with acrylic/watercolor paints and I’m wondering if you know a good and affordable gloss and varnish to use?
Hi Emma, you can look for a yacht varnish at a diy store for a strong waterproof varnish that will work well on wood.
Cheers,
Will
Hi Will, Thank you for a great post and tips. I have a question. In my paintings I operate between inks, watercolours, liners and acrylics. I am looking for best way to form isolation coat however sometimes brush activates the watercolours. Is there a spray option I could use instead of the gel please? Thank you. Wojtek
Hi Wojtek, that would be tricky due to the watersoluble nature of the watercolours. Golden have suggestions for a spray application but it would involve using an airbrush:
Golden paints – isolation coat
Can I use golden gloss medium for an isolation coat, thanks.
Hi Astrid, in theory, you might be able to, but i’d check with Golden technical support first.
Will
Hey, im working on an acrylic painting with gold leaf and i am beyond lost with how is should finish it. Do i need to apply an isolation coat? But then ive read that you cant do that with gold leaf as it tarnishes, but then i need to apply a varnish on top to seal the gold leaf, so now I’m completely lost with what to do. Any help would be great at this point thank you.
Hi Jay, it’s a tricky one with gold leaf because any form of isolation coat or varnish will affect the lustre/sheen of the gold leaf. I’d try a test piece first to see if it would still work for the look you’re after.
Will
I kind of like how my paintings look after just applying the soft gel gloss isolation coat. I’m wondering, do you even need to do a layer of varnish on top? Do some artists “varnish” with just an isolation coat?
Hi Erinn, you can leave just an isolation coat, some artists prefer no varnish at all. Although you wouldn’t be able to easily clean the surface in the future as the layer beneath the isolation coat would be the painting surface, so it’s more like a permanent varnish layer.
Will
You might have answered this question already but I put on 2 isolation coats and still have brush strokes. I’m afraid to add the varnish because I don’t know if it will eliminate the brush strokes in the isolation coat. What would you recommend to get get rid of the brush strokes? Also would you recommend using a foam brush instead of a bristle brush?
Hi Joe, the thickness of the brushstrokes will depend on the stiffness of the bristle. Have you got any softer bristles you can try a test piece on?
Will
Hello. I’m new to acrylic painting, and I deeply appreciate your valuable advice regarding the isolation coat and varnishing process. I just finished my first large canvas. I applied an isolation coat but it dried to a very uneven sheen. After two more isolation coats it looks perfect. However I noticed a small item I wish to correct in the painting before I varnish it. I have read your posts stating that one can paint over an isolation coat. If I do that, do I then apply another isolation coat (that would be a total of 4 isolation coats), or do I move directly to the varnishing coat?
How many isolation coats can be applied to a painting? How many coats of varnish?
Hi Vicky, pleased you’ve been enjoying the site. Yes, you can paint over an isolation coat and then apply another isolation coat on top of that. The number of varnish layers varies from artist to artist. Normally one of two coats, but I know some artists who layer up as many as 30 coats to create a glasslike finish.
Will
Hello,
I recently started to paint acrylic paintings, and I figured out that I need to apply isolation coat and varnish. But as soon as I applied isolation coat after 1month drying my painting it got ruined ㅠㅠ it happened in one second.. I put an isolation coat it mixed with the the colors and I totally ruined my painting.. Could you please tell me what to do? Explain please, What I did wrong?
Hi Angela, if it mixed with the colours underneath is sounds like the underlying paint hadn’t fully dried before the isolation coat was applied.
Will
G’day Will,
Don’t know if I’ll still get a response here, but here goes. Just begun painting and produce an art work I was fairly proud of – then placed an isolation coat over it before I intended to varnish it. To my horror the isolation coat seemed to melt the Indian ink portion of the detailed tree branches on the painting and I ended up with dark smudges over the sky area. The ink had dried over three days so I’m at a loss to understand why this has occurred! I overlaid the ink portions on top of the acrylic paint areas of tree branches and was wondering if this was a mistake. Is adding Indian ink (even though it is supposed to be waterproof) over top of acrylic paint a no-no I wonder? Is the chemical structure of isolation coating in general too harsh for the application of Indian ink – which allows the ink to dissolve? Thanks……… Warren
Hi Warren, yes, it sounds like the isolation coat just re-wetted the Indian ink (hope the piece can be rescued) I tend to just use it over acrylics. Not sure why it had the reaction though, as you mentioned it was a waterproof one. You could try contacting Golden technical support as they would have more specifics of the chemical make-up of the isolation coat.
Will
Hi,
For an isolation coat, can I use Winsor&Newton artists’ acrylic gloss medium instead of golden soft gel gloss ?
(I am finding it hard to find golden soft gel in my region.) And if not, is there an alternative to the golden soft gel?
Hi Nick, I haven’t personally tried the W & N gloss medium as an alternative, but in theory, it would still provide a barrier between the painting and the varnish layer.
Will
Thanks for this advice . I have Golden Extra Heavy Gel Gloss (here in the UK)… would this be suitable to use as an isolation coat ? And what varnish do you recommend to put on afterwords? Thank you
I haven’t personally tried the heavy gel gloss as an isolation coat as you may bee more water to dilute, you could check with Golden though to be sure. I tend to use Gamvar from Gamblin.
Cheers,
Will
I am new to acrylic flow painting. I want to “varnish” a few paintings to a gloss finish. I have tried applying a gloss varnish (Liquitex) directly onto the painted canvas and it always cracks when it dries. I have bought the golden soft gel gloss product and done a small test and it looks pretty good. I have a few questions:
1. I am planning to use this product as the “varnish”. does that make sense?
2. When applying it to a small area, it seamed to dry quite quickly (before I finished spreading it). Should I thin it a bit before the first coat.
3. I don’t ever plan to remove the “varnish” so was not thinking an isolation layer was needed. Thoughts?
Thanks
Hi Alan,
if you’re looking to apply one coat and leave it as a permanent fixing the Liquitex polymer varnishes should work well, not sure why they are cracking, the application might be too thick. This is from Liquitex:
Will
Discovered this specific page today and have spent hours reading every reply here. Very informative! I have a question about wall murals.
I am in the process of painting a 3-wall mural (66’11” all added up) in a church nursery on sheetrock. (Days of Creation)
The first wall is 5′ in height (from ceiling to chair rail), 35’6″ wide. It is composed of 4 vignettes (Days 1 thru 4) with 10-12″ between each of the four panels. That’s 177.5 square feet.
The second wall is 8’6″ high and 21’4″ wider with 2 vignettes with 12″ in the middle separating them. Equals to 181 1/3 square feet. (Days 5 & 6)
The third wall is 7’1″ high and 10’1″ wide, equaling 71.4 square feet. (Day 7)
This is in a very large room and is for bed babies up to 2yr olds, so I am very concerned about spills and splatters. So just from reading here, when I’m done with all the painting I plan for one isolation coat and at least 2 coats of varnish.
1) If any young one decided to lick the wall (I can’t imagine, but… have to be prepared for anything), is there any danger?
2) I assume I’d be brushing both protection layers in one fell swoop for each Day and then if there are margins (Wall 1 & 2), brush them when the paintings have been done first. At the moment I have one helper. Each vignette on Wall 1 is 91.5″ wide (3 yardsticks +8″) (with 3 marginal gaps of approx 12″ in width. Wall 2 has two vignettes which are 10′ each plus one margin of 12″ between them. The third wall is one panel/vignette itself (7’1″ x 10’1″). I think I can paint from the ceiling down to the horizon line and then work on the bottom (kind of breaking it up into 2-3 horizontal sections–for the scenes that have sky, mountainous background, and foreground). My concern is for the time and getting each section done (using each horizontal section) before it dries. Does this sound like it’s doable given the dimensions?
3) My husband said if I get 100 sq ft per gallon, I’d probably need 5 gallons (of each protection, isolation & varnish). Does that sound right? AND is there anywhere I can get these materials in that quantity (at a good price)?
I realize you deal mostly with Golden and N&W, so you might not know, but would the home improvement store have appropriate material to use–the isolation coat being permanent and the varnish to be removable & totally clear without any yellowing? Should I trust their people to know (they do seem knowledgeable in the paint department when I was getting more quantity of some of the craft paint colors). I would trust a true artist over the paint department. (Cost has to be part of the equation.)
Thank you so very, very much for your time and efforts! I look forward to exploring your site!
(My website below is undergoing a remodel. Another place to see some of my work [this project only at this point, my Instagram is just starting out–after I figure out how to create albums, I’ll be sharing other murals, acrylic paintings, and watercolors that I’ve done] would be at https://www.instagram.com/artistauthordogtrainer/ )
Hey Donna, sounds like an epic project! I haven’t really done many murals so wouldn’t want to say for sure regarding the safety/toxicity levels of the products for children. You might find this mural section on Golden paints helpful, and their technical team would be able to advise https://www.goldenpaints.com/product_support
Cheers,
Will
Hi Will,
I hope you still receive comments on this page…
I was recently told the following:
a painter used to work with oils, then had to give that up due to allergies. Now he works with acrylics but he misses that special sheen on his finished paintings.
He told me he finishes his acrylics with linseed oil. Just a thin layer over the painting.
It looked good so I tried it.
Initially, this brought out the colours of the painting really well, but then I had a problem with the surface remaining sticky. I read up about it (should have done that first, of course!) and followed the advice of letting the painting sit in the sun for sometimes multiple days.
The stickyness is indeed gone on most of the surfaces I did that with.
But here is what I am wondering about..
You talk about dust gathering. Well, I think my paintings must have gathered a lot due to sitting outside in the sun…. it is not visible (yet), but would you recommend the use of linseed oil?
When doing the isolation and varnishing, does the base material matter?
Does it work for canvas on board, or bad canvases from a cheap store?
You talk about the heat influencing acrylics. I recently had some painting in a yard show and it became pretty hot. I was worrying about the effect this would have on the painting. Is there indeed something to worry about? The paintings were out for a good 8 hours…
And finally…
I work on flat canvas (from a pad) and on mounted canvas. I love the flat canvas, even though it seems to be a bit more rough. The flat are usually framed and behind glass. If that is the case, should I still decide to isolate and varnish them? Or is the glass enough protection?
Thanks for considering these questions!
Hi Nicky,
Would you recommend the use of linseed oil?
I wouldn’t personally recommend linseed oil as a final varnish on oil paint or acrylic paint. To achieve a gloss effect to saturate the colours I would apply a gloss varnish.
When doing the isolation and varnishing, does the base material matter?
Does it work for canvas on board, or bad canvases from a cheap store?
Not really, you would apply the same on canvas or board. But usually the more expensive the material the more archival it would be.
Hope this helps,
Will
Hi Will, have enjoyed and learnt a lot from your replies.. thank you! I hv an urgent question please incase you’re free.. I mixed soft gel gloss and water for a final coat to my acrylic painting – unfortunately there were some bubbles after mixing so I’ve left it in a jar to settle. You’ve mentioned 24 hours is best for bubbles to go out of the mixture, but I need my painting ready for a show tomorr! 2 hours after mixing, the bubbles look much less (I even popped some with toothpicks .. is that okay?! How bubble free should the mixture be? I really need to add my coat soon so it’s dry enough to go to the gallery in about 8 hours! Am hoping in another hour the bubbles will be gone is it too soon to use the mixture – is there a chance even some teeny bubbles will ruin my painting? Is it best to not do it this hurriedly or do u think it will be okay? Thank you and hope to hear from u soon !
Hey Sheyna, you might have bitten the bullet before your deadline, but that should be ok. What I’d suggest it just to try a swatch on a scrap piece of canvas before committing to your piece, and you can dry off with a hairdryer to speed up the process tp check for air bubbles. Hope it goes smoothly.
Will
Just found your site and hoping you have some advice for me. I am an experienced acrylic painter but new to using an isolation coat. I have 3 new paintings that I’ve used an isolation coat on, using 2 part Golden soft gel gloss medium to 1 part water. 3 of the paintings came out fine but one didn’t seem to be covered completely, so 16 hours after the first isolation coat I did a second. That was about 6 hours ago, and I just looked and it looks like the brush picked up some of the first coat is parts of the piece are matte and parts are glossy. I’m very worried and am not doing anything to it yet, but wondering if a. I need to do another isolation coat in a couple of days of b. if it’s okay to just varnish over the whole thing. I use Liquitex gloss varnish. Thank you!
Hey Michelle, the varnish should be able to even out the slight differences in sheen. I would try a test piece with the varnish you’re using and the number of layers you usually apply with the varnish to see if it’s going to give you the coverage you’re after.
Will
Hi, I have renovated a pub sign in acrylics. Some of the acrylic pens (black especially) have a tendency to ‘drag’ when I’ve applied varnish before so I am going to use an isolation coat first. I have sprayed the sign with Winsor and Newton fixative spray to hopefully eradicate the ‘drag’. Is it ok to put the isolation coat over the top of the fixative spray? Also what varnish would you recommend as the pub sign has to endure some bad weather conditions. Is MSA Golden Varnish ok?
Sorry to be long winded
Jason
Hey Jason, mmm, not sure for a pub sign due to the outdoor exposure. The MSA varnish will be the most hardy, but for exterior woodwork I’ve often used a yacht varnish. It will have slight yellowing in comparison to the MSA varnish, but will be more hardwearing when exposed to the elements. I’d try a small sample on some scrap wood to see if you like the aesthetic.
Will
Will, thanks for such wonderful information! I had a few questions please-
1. Is it absolutely necessary to use an isolation coat before varnishing or epoxy Resin?
2. By what I am reading here, it seems like the isolation coat dries quick, so wouldn’t it leave brush strokes? I am a tad nervous as that might ruin a big painting…thoughts?
3. Couldn’t find you on Instagram…are you on insta?
Thanks for your guidance and sharing valuable information!
Hi Neha,
1. Is it absolutely necessary to use an isolation coat before varnishing or epoxy Resin?
No, you don’t need to apply an isolation coat. only if you intend to use removable varnish.
2. By what I am reading here, it seems like the isolation coat dries quick, so wouldn’t it leave brush strokes? I am a tad nervous as that might ruin a big painting…thoughts?
Try a test piece first to see if it’s the look you’re after.
3. Couldn’t find you on Instagram…are you on insta?
@willkempartschool
Cheers,
Will