Robie is an artist who loves sharing what she has learned about art and painting in the hope that it might help other creatives.
How Varnish Protects and Improves Acrylic Paintings
Acrylics get quite flat after and opaque after they dry. Many times there are uneven areas of shine and matte, due to use of different paints, retarders or other mediums that alter the look of the finished work.
A varnish makes the painting surface more homogeneous, evening out sheen, and intensifies the colors.
Conversely, depending on the effects the artist was trying to achieve, some pieces may lose their character with a unifying varnish, so it’s ultimately the artist’s choice.
Another great advantage of applying a final coat of varnish is that it seals the porous acrylic paint surface, blocking the dirt from collecting.
Dry Acrylic Paint Has a Porous Surface
After they dry, acrylic paints become durable and water resistant. However, during the drying process, the water evaporates from the paint, leaving tiny holes, which are a gateway for dirt and dust buildup over the years.
If you hang your paintings without glass, even if you wipe down and dust your paintings regularly, some amount of dirt gets trapped on the paint surface, and over time the accumulation can discolor the artwork. A sealant makes the surface dust resistant and easier to clean.
Varnish provides also a UV protection that prevents fading and yellowing of the paint.
While varnishing is not necessary, I always choose to do it. I usually apply a second coat too, just to make the surface a little shinier and the varnishing more homogeneous.
Timing - Allow a day or two for the acrylic paint to be completely dry, then apply the isolation layer (optional), and wait another day or more before varnishing.
If the acrylic paint is thick, like impasto, it’s recommended to wait a couple of weeks before applying the isolating layer or varnish.
Temperature - Ideally, the temperature should be between 65-75 F, and the humidity between 50- 75%. Too much humidity or cooler temperatures may cause moisture getting trapped between the varnish and paint layers, resulting in whiteness or opacity.
Application – Acrylic varnishes can be brushed or sprayed. When applying, watch out for foaming, non-uniform coverage, releasing of particles from the applicator, etc. Let them dry flat in a place with no dust, leaves, or other things that might fall on the wet surface.
For varnishing, use a clean, large, and flat painting brush, better if with split end bristles.
Types of Acrylic Varnishes
Acrylic varnishes are either permanent or removable and can be applied to both flexible and rigid supports.
Varnish comes in matte, satin, gloss or high gloss finishes. Glossy varnish usually enhances the colors, while satin and matte varnishes can soften the colors; in fact, matte varnish may actually lighten darker colors.
You can mix them up and acquire your own level of shininess, or apply them in layers to obtain the wanted effect.
Video: Varnishing Acrylic Paintings - types of varnishes
Tip on Photographing Artwork:
If you plan to take photos of your artwork, do it before you varnish.
Varnishes create a shine to the surface that makes your artwork more reflective, thus it gets trickier to take a good photo.
Consider Applying an Isolation Coat Before Varnishing
Before applying your varnish, it is a good idea to apply an isolation coat. However, keep in mind that an isolation coat is permanent and non-removable, and may cause changes to your artwork qualities.
Reasons why it’s a good idea to have an isolating layer:
- To prevent cloudy or frosted effect when using a matte varnish over an absorbent surface. The frostiness is due to the varnish agent being absorbed into the surface, leaving the matting agent exposed. Isolating the surface stops this unwanted effect.
- To create a physical separation between the painted surface and the varnish. This is particularly important in case the varnish will need to be removed; it keeps the painting protected during the stripping process.
One or more coats of isolation agent may be required, depending on the level of absorbency of the surface. When applying multiple coats, leave 3-6 hours in between coats, and always wait at least one day before varnishing.
It can be applied with a brush or with an air-spray method. The latter is required in case of water-soluble or unstable paints, like pastel or watercolor.
Brush Varnish Application, Step-by-Step
- Wait until the paint is completely dry.
- Work in a dry and dust free room. Clean the painting surface from dust, particles, lint, etc.
- Use a clean, rinsed jar to mix your varnish with up to 25% of water – check instructions on the varnish container. Mix the varnish careful and slowly, to avoid the formation of bubbles.
- Use a clean, large, and flat painting brush, better if with split end bristles.
- Lay the painting flat while varnishing, so the varnish doesn’t run down the canvas and dry uneven. Make sure you protect the surface underneath from drippings.
- Dip the brush into the varnish and apply with regular and even strokes, holding the brush at an angle. Be careful not to overwork it, or it will create bubbles and dry foggy.
- Check the surface looking at an angle to detect areas that are not wet and shiny and go over them with more varnish.
- When you are done, wash the brush and the container with mild soap and rinse well.
- Leave the painting flat until it dries. Allow few hours for the varnish to dry; once dry, double check the surface to see if it has an even glare. You may want to apply a second coat to make it more even or shinier.
Spray On Varnish Application, Step-by-Step
A spray on varnish is always a good option, but it’s the best choice when:
- The painting has textured surface and brush application may result in foaming.
- The artwork has a fragile surface and brush application may be disruptive.
- Spray the varnish in a well-aerated area and possibly wearing a mask.
- Keep the painting upright while spraying. Make sure you cover each area of the painting spraying continuously by moving in a smooth motion, alternating horizontal movements on one coat and vertical on the next. Slightly overlap the spray pattern, to ensure complete coverage.
- During the spray application, maintain the same distance across the surface of the painting, and move your body as well as your ark, to avoid arching the path.
- Apply each coat perpendicularly to the previous one. Turning the painting by 90 degrees helps to keep your pattern consistent.
- For best results, apply 2-3 light coats to achieve your finish, instead of one heavy coat.
Varnish Removal, Step-by-Step
Removing a varnish can possibly change and damage the appearance of the artwork, so if it really needs removal, it’s best if left to professional. However, there are times when the artist needs to do the work.
- Check your varnish package to see what kind of remover you need to use. The most common is a solution of household ammonia.
- Make sure you operate in a safe, controlled manner. Work in clean, well-ventilated area. Wear a dual filter respirator, latex gloves, and splash goggles.
- First, test the solvent on a small area of the painting.
- Get a lint-free, soft, white cloth, like a 50/50 cotton/polyester, not bigger than 2 square feet. Saturate it with the remover solution and place over an area of the varnished surface. With a plastic sheet, cover the saturated cloth to minimize evaporation.
It’s best to work horizontally. If you are working vertically, find a way to keep the saturated cloth in place on the varnished surface.
- Allow the saturated cloth to lie on the painting for 2-5 minutes, then rub the cloth gently until the varnish starts to dissolve. Be careful not to apply excessive force, as this may damage the paint layers underneath.
- Repeat the procedure, for the entire area to be cleaned. If you see any paint color on the cloth, stop right away and allow the surface to dry.
- Allow the painting to dry completely before applying a fresh coat of varnish.
To Varnish Or Not To Varnish?
Whether an acrylic painting should be varnished or not is an old dilemma. There are acrylic artists supporting either side.
The decision is up to the artist's desired look for the finished painting.
While the varnishing is not necessary, I usually do it, both to add a protective layer to my paintings, and because I really like how it makes the shine on the painted surface consistent.
For some of my work I love glossy varnish. For other pieces I love a satin surface. Ultimately it is every artist’s decision to ponder the pros and cons of varnishing and see if their work would benefit from it.
Should You Varnish Acrylic Paintings?
Advantages and the Disadvantages of Varnishing Acrylic Paintings
- The varnish coating offers UV protection, which helps slow the fading of the pigments.
- With varnish, the dirt and dust can be removed easily and isn't trapped in the acrylic layer.
- Many artist varnishes can be removed with an ammonia solution. This comes in handy if you have to clean a permanent stain of in case the varnish layer yellows with time, you can remove it and reapply it.
- Varnishes are a great way to even out sheen and pull the whole painting together.
- A varnished painting handles better the battering from handling and shipping.
- Single coats of varnish that even out the entire sheen may not be the original artistic intentions, altering the artwork negatively.
- Sometimes varnishes can be difficult to apply. Some problems being: running varnish, wilting of the artwork, visible brush strokes, formation of bubbles, etc.
- Some varnishes are not removable. If something goes bad during shipping or on display, and the artwork gets stained, you can’t strip the stained varnish off and apply a new coat.
- It's an extra step for the artist.
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
Questions & Answers
Question: Can I use matte varnish over a too shiny one on an acrylic painting on canvas? I'm using Liquitex products.
Answer: Well, Liquitex varnishes can be intermixed for a customizable sheen, when still wet, that is. That makes me guess that even when dry it would not be a big deal if you re-coat with a different varnish.
However, I have never re-varnished a painting with a different sheen coat myself, so I'm only writing my best guess.
I would give it a try. However, if you care a lot about this particular painting, maybe contact Liquitex directly - they have a contact form on their website - and see if their experts have different suggestions.
If you decide to re-varnish, me sure that your surface is clean from any dust, dirt, grease, or other deposit. You don't want to encapsulate those in between varnishes.
Question: I never see brand name recommendations on varnish. What varnish brands would you recommend?
Answer: When brushing the acrylic varnish on, I use Liquitex or Golden. I also like the Grumbacher spray varnish.
Question: I paint with acrylics on hot-pressed 300# Arches watercolor paper. I've never varnished but am convinced here that I should. I always apply Golden Soft Gel (gloss) to my work. Which varnish do you recommend for my art?
Answer: A spray varnish would get the job done nicely and easy. Follow directions on the can and you'll be fine.
Question: I am fairly new to acrylic fluid art painting. I am using Liquitex gloss varnish and a sponge brush to apply. I can't seem to avoid brush marks. Is there a better tool that I can use to avoid brush marks in the varnish?
Answer: When using acrylic varnish, you can dilute it by adding up to 25% of water. Thinning the varnish this way makes it less dense and it should solve the problem of brush marks showing after it's dry.
Question: I tried the spray varnish and everything was fine. Then I tried using liquid varnish and I noticed my paint smudges (like it is not completely dry, but it is for a few days and I don't paint in thick layers). Could this be due to the poor quality varnish, or I should have waited for longer?
Answer: If when you brush your varnish your painting smudges, I would think that it's not the varnish at fault, but the painting medium. Was it an acrylic painting? I would be very surprised if an acrylic painting still smudges after days unless you used a slow drying kind of paint or added a slow drying agent. In that case, you may have to wait a few more days before you varnish.
However, I'm more inclined to think that you may have used some kind of water-soluble medium in your painting, like markers, watercolor pencils, charcoal, pastel, or any other medium that would be moved around by a wet brush.
If that's the case, no matter how long you wait, the problem will be there when you decide to apply your liquid varnish.
My recommendation is that you spray with a fixative (and let dry) before brushing the varnish on. (Try it on a sample piece to see if it works before risking to mess up your work.)
Or you could apply a few layers of a spray varnish and be done with it.
Advice: Double check on a test piece that whatever treatment you do, it seals the painting and it does not smudge in contact with a wet rag.
Question: What about cracking, I'm using Liquitex gloss medium varnish. I'm mixing it with 25% water and putting it onto my painting. After about an hour the entire surface has micro cracks, the varnish cracked everywhere. I tried pouring without water and just got very big cracks. How can I better prevent cracking in my varnish?
Answer: Oh boy, that sounds very serious and so annoying!! I really don't know what might have caused the cracking. I would recommend that you contact the Liquitex customer service and explain the situation. I hear that they are super helpful.
Question: Where do I find or how do I make a split end bristle brush?
Answer: I'm not sure where to find a split end brush, but I would use an old brush or buy a cheap brush and use scissors to make the split ends just the way I like it.
You can start by cutting off a little of the central bristles then try painting a stroke, to see if you like the effect, then gradually adjust to your liking.
I'm guessing the major art suppliers may have split end brushes in stock, though it might be tricky to search if they call them something different. You may have to peruse brush inventories and find out how they are called on the catalog.
Question: I have used a gloss Liquitex acrylic varnish over my acrylic painting and the coating of it is uneven. I am wondering if this is due to the fact that I have used iridescent paint and metallic paint in areas. Does the varnish absorb into the canvas, because over these areas the varnish appears flat? I did give 2 coat coverage-of varnish, painting it on horizontally for the first layer, then vertically for the second layer.
Answer: Different paint applications dry with a different texture. If the paint is thick and smooth, it becomes a very flat surface. If the paint is thinner or mixed in with a coarse medium, it has some texture after it dries. This difference in surface quality, when using glossy varnish, can create patches of very shiny varnish on top of the slicker areas, or sometimes little puddle -like areas where the paint is thinner and dried to a slightly lower level than the surrounding strokes.
My suggestion is to apply more varnish and take everything to a very shiny level. As an alternative, I have gone for a plan B in the past (but I warn you that I'm not sure if it has any side effects in the long term).
My plan B was to fix a painting with random spots of more gloss, and less gloss has been to use satin spray varnish over the whole thing to take the shine down and make the painting more uniform.
A. You keep adding gloss varnish until it all becomes very glossy (wait for layers to dry in between).
B. You re-varnish with a satin varnish and take down the whole sheen, but I kind of think this is not recommended by varnish manufacturers, though in my reasoning it's still a type of acrylic binder and it should be compatible.
Question: Can I use acrylic ink for outlines over dried heavy acrylic paint?
Answer: Acrylic ink is a super fluid acrylic paint and is completely compatible with all other acrylics, so I would say yes, you can use acrylic ink over dried acrylic paint.
Question: After two days, the varnish on my acrylic painting still feels sticky - how can I correct this?
Answer: Usually, acrylic varnish dries pretty quickly. However, I varnished some oil paintings with a varnish that was suitable for acrylics and oils, and it was sticky for longer than a week.
My only suggestion would be to wait and let it dry. It will dry at some point.
You may be able to accelerate the drying time a bit by keeping it in a warm (not humid) environment, or by using a hairdryer, but I would not touch the varnish or try to remove it while sticky.
Question: Is it ok to mix gloss and satin acrylic varnish to get a mid-shine effect?
Answer: Yes, I've done that in a few occasions and it looked good.
Question: Can varnish be used to brighten a faded painting?
Answer: Glossy and semi-gloss varnish recreate the look of the wet paint, as well as make the colors look deeper and a little juicier. However, varnish does not add coloration to the paint. If the painting for some reason has faded, varnishing it will not bring it back to the original look.
If you are dealing with an old painting, I would not apply any varnish unless you are confident that 1) The surface is clean from any dust or residue; 2) The surface has no previous varnish application.
If you are trying to restore it, I recommend talking with an expert, or you may end up making the damage worse.
Question: The instructions on my acrylic varnish say not to mix with water. Should I add water anyway?
Answer: I recommend you read the instructions on the acrylic varnish container. If it does not say add water, then I would not add water.
Question: Is writing possible after varnishing or before varnishing?
Answer: I like to complete all the painting and mixed media applications before varnishing.
Question: Can I also use varnish for watercolor paintings?
Answer: As far as I know, you don't varnish watercolors, but you frame them under glass.
Watercolor paint would re-activate in contact with a wet varnish or other medium, and the painting would be ruined.
Question: I used Liquitex gloss varnish over my painting 4 thin coats. I applied it vertically, which I realize was a mistake and I should have done it horizontally. Can I apply the Satin varnish horizontally to fix my unevenness from the Liquitex?
Answer: Yes, I would try that.
Before you apply new coats of varnish, make sure you brush off any dust that may have accumulated.
Next time, try to switch between horizontal and vertical strokes at each layer of varnish.
Or, just apply varnish in random directions, any visible brush stroke can add a painterly interest to the surface.
Question: Is there an acrylic varnish product that creates texture at the same time? I've seen a print varnished so it looks like brush strokes. Any idea what this might be?
Answer: I've seen those paintings too, they have a texture that looks like big brushstrokes all over the surface. I am pretty sure the effect comes from the way the gesso was applied, even if it appears to be the varnish. As far as I know, varnishes don't create texture. You can apply the gesso roughly before you even start painting or create the wanted effect using impasto or molding paste.
If you have more questions, I'd try the Liquitex and Golden websites. They have a lot of information and their customer service is great at responding to inquiries.
© 2012 Robie Benve
Robie Benve (author) from Ohio on March 07, 2020:
Check the Q&A section, this was answered there :) Thanks
Kate on March 05, 2020:
Hello! I made a mistake varnishing. I used the liquitex gloss varnish 4 very thin coats. I applied it vertically.. .and I know i should have done it horizontal. it is uneven.. My question is can i go over the paintings again all with Satin varnish? And can I do it horizontally this time? Or since I did the other 4 coats vertically do I need to stay that way. Thank you!
Robie Benve (author) from Ohio on March 04, 2019:
Hi Katya, it sounds like the area that became muddy was not painted with acrylic, but rather with a medium that was water-soluble.
To protect an area that may smudge at the touch or coming in contact with liquids, spay it with a fixative.
Katya on March 02, 2019:
I have varnished my acrylic painting but one of the elements seems to have changed colour and became unpleasantly muddy! Is there a way so I can fix this particular area?
SelviGanesh on January 07, 2019:
Nice suggestions for begginers.
Robie Benve (author) from Ohio on February 20, 2017:
Hi Penny, it sounds like a matte or a semi-gloss varnish would have been a choice that you would have liked more. Sometimes is hard to pick, and it sure is very hard for store employees to give the right recommendation. Personally, I don't have any experience on re-varnishing with a product of different shine. In theory I would think it's ok, but having no personal experience on this, I don't feel comfortable giving you a definite yes or no answer. It sounds like a question for the Krylon company. Have you tried asking the question on their website, they have an Ask Krylon section, where you can submit questions to their experts.
Penny on February 19, 2017:
Hi and thank you. I'm not sure if my last question sent to you. If it did please egnor this post. What I was wondering is, if I top coated with krylon clear gloss and I find it to glossy can I cover it with a krylon matte? I've seen post that you can and was told I could when I bought the gloss but I'm nervous to try it on my painting, thank you
Penny on February 19, 2017:
Thank you for your help. I have a new problem now. I did a painting for my daughter in law and varnished it yesterday. This time I used krylon gloss as recommended by an artist/employee where I buy my artist supplies. I feel that it's too glossy and has a glare when light hits it. Can I safely use a matte over it to kill the glare? I'm pretty stressed. I was told and have seen comments where people say you can always use a matte over gloss if it's too shiny. Do you know if this possible or not. My family says it looks fine, but I'm not happy. It brightly colored with some misty fog so l wanted the gloss and the pop of color. Just not quite this glossy
Robie Benve (author) from Ohio on February 17, 2017:
Hi Penny, The recommended way to go is to remove the old varnish and reapply. Depending on what you use, you may have to use different solvents to remove it. The appropriate solvent is usually indicated on the spray can, under "uses".
For a shortcut, if you used an acrylic coating, a new coating could probably stick to it with no problems, and you could adjust the shine that way. However, after one year the surface has already started collecting dust particles and dirt, so I would first make sure I get that surface cleaned well before applying a second coat of varnish. You don't want to trap dirt particles in the layers and compromise color and stability of the paint. Hope this helps..
Penny on February 16, 2017:
Hi, I did a painting a about a year ago as a gift for someone. I'm always nervous to topcoat, but know how well it protects my pieces. We debated on the shine and I ended up using a Matt. It didn't dull the colors. It looked pretty much the same as before topcoating, with a very slight sheen. But now I'm wishing maybe I had chosen a glossier spray. Can I apply a gloss spray over my lightly Matt coated painting. It's been over a year since I sprayed it and the matt had a slight sheen to it? Thanks Penny
Robie Benve (author) from Ohio on September 08, 2014:
Hi CherylsArt, I have to admit that I have learned about the isolation layer from professional training, but I have never used it myself. I thought it would be fair to mention it for those that want to go that way. :) thanks!
CherylsArt on September 01, 2014:
The isolation layer is new to me.
Robie Benve (author) from Ohio on December 10, 2012:
I did some outdoor painting years ago, and I used the outdoor craft acrylics, which also had their own varnish. I can't say if it was weather resistant because it was on the cement step outside our door and it faded by friction before it got damaged by the sun! Not a long-lasting masterpiece! lol
Thanks a lot for your comment and voting up etc. :)
Mary Hyatt from Florida on December 09, 2012:
Interesting Hub. The only time I use acrylic paint in on outside projects like art work on a fence. I also make woodcrafts that stay outside. I used varnish a couple of times till I realized that in the Florida heat and sunshine, the varnish crackles and turns yellow.
I've only used oils on canvas.
Voted UP, etc.
Robie Benve (author) from Ohio on December 07, 2012:
Hi Lori, thanks so much for your great feedback. Happy painting! :)
By Lori from USA on December 06, 2012:
I paint with acrylics and didn't know most of this ! I love the little bird in the top painting.
Robie Benve (author) from Ohio on May 22, 2012:
Hi pamella, I usually use Liquitex heavy body or Golden acrylics, but I like the Golden better.
For the bird - thanks for the compliments - I mixed the paint with modeling paste to create some texture, and I used a spray gloss varnish by Grumbacher. If I brush on the varnish I prefer a polymer varnish.
Thanks for your comment. :)
pamella on May 22, 2012:
Great article. I left acrylic paints just for the reason they dry so matte. I am really getting tired of waiting for my oil paint to dry, and was thinking of going back to acrylic. What brand of acrylic paint did you use on your beautiful bird? And what brand of varnish did you use?
Lela from Somewhere near the heart of Texas on May 19, 2012:
I always wondered why some acrylic paintings look more like oil paintings. This may be a clue. Thank you.
Robie Benve (author) from Ohio on May 04, 2012:
Summerberrie, I'm glad you found it interesting. :) Thank you!
summerberrie on May 03, 2012:
Robie Benve, this hub includes some wonderful information and tips on varnishing pictures. Great detail!
Robie Benve (author) from Ohio on May 03, 2012:
@Eliza, being messy can be lots of fun, especially if you do it with a puppy's energy and cheerfulness. Good for you! :)
@Margie, I appreciate your comment and feedback, thanks!
@Marcy, You sure can apply the varnish long after, just make sure there is no dust and dirt on the surface. But wait, why do it on old stuff when you can restart painting and produce some (I'm sure) amazing artwork today? Thanks for stopping by and commenting. :)
Marcy Goodfleisch from Planet Earth on May 03, 2012:
I wish I'd had this information when I painted a few things years ago (and I should start painting again, right?). Can you apply these protections long after the fact? I haven't produced anything as great as your picture at the top, but my descendants might want a keepsake or something one day!
Great hub - voted up, useful and interesting!
Mmargie1966 from Gainesville, GA on May 03, 2012:
Great step by step instructions to accomplish the desired look. Voted up and interesting!
Lisa McKnight from London on May 03, 2012:
Yeah Robie that is exactly my problem. Messy puppy is me.
Robie Benve (author) from Ohio on May 03, 2012:
ElizaDoole, acrylic are not that bad, c'mon. ;) The tricky part is that they dry quickly, so you have to put them on the right spot, or it'll be difficult to take off, especially from clothes. That can definitely be messy business. Thanks for your nice comment. :)
Robie Benve (author) from Ohio on May 03, 2012:
europewalker, I feel your pain. The most difficult part for me is to take my time and varnish slowly and carefully, to avoid bubbles and brush strokes. I appreciate you spending time reading/commenting. Thanks. :)
Robie Benve (author) from Ohio on May 03, 2012:
Thank you Peggy and alliemac for your kind comments and for sharing my hub on your social networks, it's truly appreciated. :)
Lisa McKnight from London on May 03, 2012:
I really like your bird painting. I admire anyone who can paint. Acrylic seems like a messy business but you make it sound very logical and clear. Great information thanks. Voted up.
europewalker on May 03, 2012:
Good tips, there have been times when my paintings looked ruined with visible bubbles and brush strokes. Quite frustrating! Useful hub.
alliemacb from Scotland on May 03, 2012:
This is a really useful hub and the information is so easy to follow. Since my father retired, he's been dabbling in painting so I will definitelypass this on to him. Voted up, useful and shared on Pinterest.
Peggy Woods from Houston, Texas on May 02, 2012:
What an interesting article. It has been a while since I have hauled out my paints and created anything on canvas. Thanks for telling us about the pros and cons of varnishing acrylic paintings. Voted up, interesting and useful and will SHARE with my followers.