Adding an Isolation Coat to an Acrylic Painting

golden-soft-gel-gloss

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.

isolation-coat-acrylics-golden

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 GlossAdding an Isolation Coat to an Acrylic Painting

Adding an Isolation Coat to an Acrylic Painting

 

 

This Post Has 495 Comments

  1. Edwina

    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

    1. Will Kemp

      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

      1. Edwina

        Thanks Will for the quick response.
        Edwina

  2. Maryellen

    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!

    1. Will Kemp

      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

  3. Lesley Crawford

    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

    1. Will Kemp

      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

      1. Lesley Crawford

        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

        1. Will Kemp

          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

          1. Lesley Crawford

            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 :-)

          2. Will Kemp

            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

          3. Lesley Crawford

            OK, thanks again for your advice, it is much appreciated :-)

  4. Kim

    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.

    1. Will Kemp

      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

  5. Addie

    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

    1. Will Kemp

      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

      1. Addie

        Hi Wil
        thanks for taking the time to reply. I did find the answer in the comments section.

  6. Linda Bass

    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

    1. Will Kemp

      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

  7. Carina

    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.

    1. Will Kemp

      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

  8. Joann Quinlivan

    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?

    1. Will Kemp

      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

      1. Joann Quinlivan

        Thanks, Will. I will leave off the isolation coat and see how it goes.

        Joann

  9. Deborah Franklin

    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!

    1. Will Kemp

      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

  10. 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

    1. Will Kemp

      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

  11. Jeffrey snith

    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.

    1. Will Kemp

      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

  12. Julia Z

    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!

    1. Will Kemp

      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

  13. Cynthia

    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.

    1. Will Kemp

      Hi Cynthia, a modern varnish such as Gamvar by Gamblin can be applied to both acrylic and oils.
      Cheers,
      Will

  14. Laura

    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

    1. Will Kemp

      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

  15. Gabriel Morrin

    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.

    1. Will Kemp

      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

  16. Marie-Claude

    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!

    1. Will Kemp

      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

  17. Yvette Dadon

    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

    1. Will Kemp

      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

  18. Grace

    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!

    1. Will Kemp

      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

  19. Betsy Nielsen

    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

    1. Will Kemp

      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

  20. Vava

    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

    1. Will Kemp

      Hi Vava, yes, you can varnish directly the varnish will be a permanent fixture on the painting.
      Will

  21. Kevin

    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?

    1. Will Kemp

      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

  22. Lisa Ullman

    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.

    1. Will Kemp

      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

  23. Vanessa

    Hi, can I use Windsor and Newton Galleria gloss medium (not gel) as an isolation coat? Thank you.

    1. Will Kemp

      Hi Vanessa, Liquitex suggest using a Gloss Medium for their isolation coat, so in theory, yes, but I haven’t personally used it.
      Will

  24. Maggi

    Will I have varnished my acrylic painting without an isolation coat. Can I add it now over the varnish and then revarnish?

    1. Will Kemp

      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

  25. Kasia

    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?

    1. Will Kemp

      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

  26. Barbara

    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

    1. Will Kemp

      Hi Barbara, nice to hear from you.

      what’s the rationale for not doing a second isolation coat when we “mess-up” and have the outcomes I described?

      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

  27. Desirae

    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?

    1. Will Kemp

      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

  28. Laura

    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

    1. Will Kemp

      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

  29. Peter

    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.

    1. Will Kemp

      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

  30. MacKenzie

    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

    1. Will Kemp

      Sure thing MacKenzie, that would be fine.
      Will

  31. emma

    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?

    1. Will Kemp

      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

  32. Wojtek

    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

    1. Will Kemp

      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:

      Spray Application
      If you want to spray and have access to an airbrush or spray gun, then use 2 parts GAC 500 to 1 part High Flow Medium. Two to three coats should provide substantial coverage although more may be applied if necessary.

      To determine if you need to apply a second or third layer of isolation coat, once the first coat is dry look at the painting at an angle and an even sheen should indicate an even surface ready for varnish. If the surface is not even then apply another coat.

      Golden paints – isolation coat

  33. Astrid Notte

    Can I use golden gloss medium for an isolation coat, thanks.

    1. Will Kemp

      Hi Astrid, in theory, you might be able to, but i’d check with Golden technical support first.
      Will

  34. Jay

    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.

    1. Will Kemp

      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

  35. Erinn

    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?

    1. Will Kemp

      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

  36. Joe

    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?

    1. Will Kemp

      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

  37. Vicky Menozzi

    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?

    1. Will Kemp

      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

  38. Angela

    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?

    1. Will Kemp

      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

  39. Warren

    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

    1. Will Kemp

      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

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