View Full Version : varnish gouache?

08-28-2006, 05:41 PM
I'm returning to an old love, gouache, for some small paintings. I just cannot get acrylics to flow smoothly enough for detail work, and I find them 'greasy' on smooth surfaces; I know there are mediums that can be added, but gouache does the job fine for what I need here.

However, I do want some of the protective and long lasting qualities of acrylics,and have been trying different varnishes, sprays etc;..does anyone have any experience of varnishing/protecting gouache, or should it always go under glass anyway?

cheers m'dears

08-28-2006, 09:07 PM
Gouache doesn't need varnishing to last a long time, it just needs protection from getting wet and accumulating dust. A raised glass does that well.

There are acrylic "gouaches" on the market that have a similar look, such as Holbien's Acryla Gouache, but they dry permanent. I still see a bit of an synthetic look in them, but they are an alternative.

Richard Saylor
08-28-2006, 11:23 PM
Gouach produces a porous paint film which can make it hard to clean. Any varnish which works for watercolors should be okay for gouache, but it will change the appearance of the paint film. I prefer glass.


08-30-2006, 12:33 PM
Can Gouache take a high sheen varnish so it appears to look like an oil painting? If so, what kind of varnish?

I would prefer to preserve the painting and not rely on glass, which can be easily broken overe time, or collect moisture on the inside.

09-19-2006, 01:56 PM
I've been looking for around for a varnish too - I've found these;


I think the spray from Talens is worth a try... I let you know how it goes when my order arrives.

Alachua Artist
09-29-2006, 11:19 AM

I work extensively with gouache and (almost) totally ruined a painting that I varnished with Windsor & Newton gouache varnish. I wanted to give the gouache a more protected finish so it wouldn't have to be behind glass. I did quite a bit of research and even performed a "test patch" on a sample painting. Everything seemed fine until I varnished one of my finished pieces.

Holycrapwhatamess!! It dried to a milky film over the entire painting. Many many bad words were said over this! I tried EVERYTHING to get it off, but alas, it was set. With all the workings and rubbing and effort, it polished up into a high gloss. The painting looks washed out, now, and very shiny. Not like gouache at all, and definitely NOT what I had wanted or planned on.

No varnish for me! It's glass all the way.

09-29-2006, 11:29 AM
I know that feeling! The last gouache painting I tried to varnish turned milky too, and I may have sworn once or twice too.

I figured the varnish I used wasn't designed for gouache, so find one that is. I admit I didn't know W&N made one specifically for gouache, but the can I've ordered from Pebeo looked promising...

Perhaps I'll spray an unwanted painting as a harsh test for this stuff before I dive in wholeheartedly.

Thanks for the warning, but is glass really the only alternative? (I'm planning a 6ftx4ft painting, and that's a whole lotta glass!)

Alachua Artist
09-29-2006, 11:37 AM
...but is glass really the only alternative? (I'm planning a 6ftx4ft painting, and that's a whole lotta glass!)

Some of my larger paintings (4'x5') are framed with plexiglas instead of glass. It's lighter in weight and less likely to break.

I do hope you are taking photos of this billboard (just teasing). Is this a commercial installation or just work you are doing in your studio?

09-29-2006, 11:40 AM
If it was spray varnish, it might have been humidity (of any sort) that was trapped by the spray that may have caused the milky film/haze to appear. Being in Alexandria, Va., I suppose you get some high humidity. When I lived in North Florida, I often used spray varnishes, but could only spray under low humidity conditions (not easy to do in Florida), often I had to spray indoors, all windows closed, with the air conditioner on ( I wore a heavy duty air filter mask, the neck hurting kind!)... or I'd get lucky in the winter and be able to spray outdoors, but only if the humidity was below 50%.

Mark: What about clear plexiglass? Costly, I know, but it doesn't break and it weighs less than glass. Just an idea for you to consider.
Oops! I see Alachua had the same thought! :lol:

09-29-2006, 11:54 AM
Plexiglas is a good plan - I tend to avoid it because I often use pastels over gouache - but it might work on this one.

Humidity might be reason... I remember it was summer when 'the incident' occurred. It's the best theory I've heard yet.

09-29-2006, 12:38 PM
Plexiglas is a good plan - I tend to avoid it because I often use pastels over gouache - but it might work on this one.

Humidity might be reason... I remember it was summer when 'the incident' occurred. It's the best theory I've heard yet.Mark,
Well, I can only say that 20 years of personal experience with spray varnishes and the effect of humidity is the only credit to my theory I can give you :eek: :D And, when I say spray only in low humidity, I mean something around 40% or lower...the weather channel was my favorite program on TV at the time... :lol: :lol:

hope you show us what you'll be working on, or the finished piece!

09-29-2006, 02:56 PM
The more I think about the varnish the more I think it's a bad idea... I just can't imagine getting an even finish on a 6'x4' area. I'm thinking paper behind plexi is the way forward... (or, hey, here's an idea - Painting on the reverse of the plexi?)

I do hope you are taking photos of this billboard (just teasing). Is this a commercial installation or just work you are doing in your studio?

This is a purley personal effort, something to get my teeth into and to keep me sane between paid jobs. I will take progress photos if I ever get it started! I seem to be too wrapped up in the "nuts n bolts" of it right now. Other excuses for not starting include sourcing materials, too much paid work and... well, it's terrifying me!

Alachua Artist
09-29-2006, 04:19 PM
Other excuses for not starting include ... well, it's terrifying me!
oh c'mon baby - the water's just FINE!!

03-09-2007, 04:20 AM
OOhhh ! I'm afraid, now, to varnish my gouaches :confused::confused: And what about matte acrylic spray ????? I want to keep the matte effect of the gouache. I don't want them to becom glossy :mad: I need help :crying:

09-26-2007, 11:21 AM
I really don't like having to use glass or Plexiglass, so I spray gouache paintings with Krylon clear spray You can buy it at Michael's I use the UV protectant type. THe support is Ampersand claybord (textured) or pastelbord so it's not a smooth surface to begin with so it avoids being glossy. I ove the results, but if you're skeptical, try it on a small, quick, 5x7 painting first.
Rita Goldner www.ritagoldner.com

10-23-2007, 06:01 PM
I, too, have used the Krylon clear spray on guache as well as casein. In one case, I had overworked and diluted the casein on a face so that it "pruned" upon drying and I was desparate to try to revive the painting if possible. The Krylon spray took the pucker out of the overworked facial area and the painting was saved.... but it is now shiny... still, I'm glad to have saved the artwork and most ppl don't know it was supposed to be a flat surface.


12-26-2007, 10:00 AM
I was given some acrylic gouache & was wondering if it could/should be varnished? If so, is an acrylic varnish (matte finish) recommended? I haven't painted anything with it yet - it's a whole new medium for me.


12-26-2007, 11:00 AM
I love acryl-gouache! There's a Japanese firm (I forget the name, sorry!) that produces a wonderful range - I think they make varnishes too, but honestly I've never needed to use them, the matte finish of the paint is too nice to spoil.

If you absolutely have to varnish it then a matte acrylic varnish should do the trick.

I still haven't found a good varnish for regular gouache though...

12-26-2007, 11:13 AM
Thank you Mark,

That's the brand I have I guess as there's a lot of Japanese writing on the tubes - it's Acryla by Holbein & I have no idea what to do with it!

Since my post above, I found lots of other info on varnishing but not a lot on acrylic gouache - would more info be found in the acrylic forum?

I'm anxious to give them a try but trying to figure out what kind of support and how to handle them.

Again, thanks for your reply.


12-26-2007, 03:49 PM
There's another Japanese brand named Turner that also makes an acrylic gouache product.

This particular medium is essentially acrylic paint, and you might as well treat them that way. Varnishing is not absolutely required, but doing so makes it easier to care for in the future, plus there would then be no need for glass. The acrylic forum would have more specific info on what kinds of varnishes are best for acrylics. I would suggest a spirit based varnish, myself. A matte varnish would maintain the same luster the paints already have. I would not recommend varnishing genuine gouache.

Richard Saylor
12-26-2007, 11:05 PM
I have experimented with a couple different brands of acrylic matte varnish, and they tend to give a plastic look to surfaces to which they are applied.

Holbein Acryla Gouache has a matte finish which looks almost like real gouache. I would hesitate to apply acrylic matte varnish to a painting done with Acryla because it would impart an acrylic look to the painting.

Applying acrylic varnish to real gouache would be problematic anyhow since it is water base and gouache is water soluble.

Here's another thing to consider from an archival standpoint. The final varnish should be non-permanent so that it can be safely stripped from the painting in case the surface gets damaged or discolored. Acrylic varnish is permanent. If one is seriously interested in protecting a painting, it should receive two coats of varnish, the first one permanent, followed by a final removeable coat. (This is the standard procedure of many oil painters.)

If I really had to varnish a gouache painting, I would simply coat it with a non-permanent spray varnish, the kind which is removeable with mineral spirits. Of course, even a spirit based matte varnish can alter the appearance of the paint surface unless a very, very thin coating is applied, and I would wonder if such a thin coating would really protect the painting adequately. (I've tried all sorts of matte varnishes on watercolor paintings, and for me they all tend to affect adversely the appearance of the paint surface.)


12-27-2007, 09:03 AM
Thank you all for your replies - it doesn't sound as if it's a good idea at all to varnish even the acrylic gouache.

Now, I just need to go in search of more information on how to use it!


12-27-2007, 10:52 AM
Thank you all for your replies - it doesn't sound as if it's a good idea at all to varnish even the acrylic gouache...

It's a good idea to protect the surface of your painting. Varnishing is one of the means of doing so, glass is another, and both have their pros and cons. Acrylic paint is very sturdy, and can resist light cleaning or dusting rather well, but tends to attract dust and grime more so than other mediums. Varnish or glass gives you more insurance against damage by cleaning.

Varnishing also helps even out the sheen or luster of the paint surface to some degree, which is most noticeable when looking at the painting from an angle. Some paint pigments have a "sunken in" quality to them where they look dull or matte next to other colors, particularly ochres and umbers, and varnishing can help to even that out. Unfortunately, in most cases it also will change the subtle values to some degree, especially the lighter washes. This is less noticeable in acrylic mediums like the Acryla since the binder is more resilient than gum arabic.

The recommended method of varnishing acrylic paintings is to apply a permanent isolation coat between the varnish and the paint surface. Then, if the varnish ever needs to be removed, doing so will not harm the paint surface. There are specific products designed for this rather than acrylic mediums, like Golden's Matte Soft Gel or Liquitex's Matte Varnish, that could then be varnished with matte MSA Varnish or Soluvar.

Glass is another option, but has physical issues of added weight, size limits, and fragility, plus it won't do anything about the surface sheen. Non-glare glass or plexi is also more noticeable than regular glass, to my eyes.

01-06-2008, 11:12 AM
Has anyone tried Golden's spray? http://www.goldenpaints.com/technicaldata/archvarn.php I went to buy some yesterday and the clerk talked me out of it (young kid who did not know what it was ;)) as it did not say watercolor on the label but it clearly says watercolor on the site at the above link.

I love watercolors and am just starting to use gouache and also hope to avoid having to put paintings behind glass. I will have to buy some next time I am at the store (2 small kids & 1 hr drive so not sure when that will be ;)) and will let you know the results :)

01-06-2008, 01:53 PM
"...it is recommended that you do NOT use it for fixing, top coating, or varnishing [gouache], unless first testing and experimenting thoroughly."

In my experience, the MSA varnish can drastically change the color of some areas of paint, like I mentioned earlier, especially if there's a smooth transition from opaque to transparent. But, by all means do your own tests and let us know what you find.

01-10-2008, 09:44 AM
oops thanks David I missed that ;)

09-28-2009, 11:19 AM
I'm new here, and I hope you all don't mind my chiming in. I'm learning how to paint, but for years have made assemblage pieces. (Mostly 'found objects' that I made myself. Because you can't always find what you need!) For so many years, I was distressed at how my pieces looked behind the glass. The colors seemed to be flattened and changed. I needed a special type of glass for a project, and went to a stained glass supply.

Wow - it hit like bricks and stones. All the glass I've ever used for framing etc. had been tinted a blue to green. That's the iron oxide in the glass, tinting it. (If I remember correctly.) I bought something called 'machine reproduction' glass that is neutral and the difference is incredible. The colors really popped and looked fantastic. If you are discontented with the glass you are using, go to a specialty glass supplier or stained glass store, and look around. You can tell the neutral panes right away from anything with color by looking at the edge of the glass. It is expensive - much more so that regular framing glass, but for me, it was worth it.

(By the way - sometimes there are imperfections in the machine repro glass - it's best to look at the pane you are going to buy in good ,lighting if a flaw will affect your piece too much. Most of the flaws are wavy spots in the glass, but I've found reasonably large pieces without flaws.For the work I was doing, some flaws made it look even better to me, but I don't know that it would please a painter!)

Good luck with your projects!

04-13-2011, 04:38 PM
When I worked as a studio textile artist, all the works were executed in gouache and we finished each one w/ a generous spray of Krylon varnish. No ill affects to any.
Here's some gouache basics: http://fruitflowerinsect.blogspot.com/2009/01/gouache.html

12-22-2017, 11:40 PM
The first gouache artist I ever knew always used a clear gloss spray varnish. He just used whatever brand was available, Krylon, clear spray paint, anything. He loved the effect of the gloss varnish on it - he did astronomical scenes with large areas of black. The matte look didn't really give a sense of outer space, but once the gloss was on the black deepened and it gave an impression of looking through a porthole onto an airless moon surface (most of his scenes were rocky moonscapes and planets without atmosphere.)

I loved the effect and naturally thought of using it.

For the poster who got the milky effect - I've used matte spray varnish for decades on pastel paintings for fixative. One day a can that a friend gave me had been left out in her car for several days in freezing temperatures. I lost a good pastel sketch to that same milky phenomenon. It's not just humidity. Extreme temperatures can make fixative or varnish coagulate inside the can. Once a can is ruined this way, it'll still happen no matter what you use the can for. If I got a new can of varnish that did that, I'd take it back to the store and demand money back, warning the shop about temperature ruining spray varnishes and fixatives.

That it was a summer project tells me that heat could do the same thing. Of course extreme heat can also make the can explode, not a good thing.

Now what I do is test patches with any can of fixative or varnish, just to find out if something went wrong with the can before I used it. But my friend up North wasn't brand fussy, he just wanted it to be gloss and he used more than one light coat to get a good thick clear coat.

Because gouache includes some fugitive colors, it would make sense to also get one that has UV-protecting qualities and is archival, because if it yellows, your painting is ruined forever or at least changed. And if it's UV-protective, then that would be some help when you hang it. I don't hang gouache paintings in sunny rooms or somewhere that direct sun would fall on it. When people are looking at it in electric light that's not as bad, but direct sun can change the chemistry and shorten the life of the painting.

Many of my gouache paintings are in sketchbooks anyway, so whether I varnish or not isn't as much of a problem. But a varnish coat may protect that page from spatters or humidity too.

My set of Maimeri tube gouache included a bottle of clear varnish in the box. Eight colors and a bottle of varnish that could be sprayed with a mouth atomizer. I bought a mouth atomizer to use with it but then mislaid the varnish when I was keeping the tubes somewhere other than the box. Oops. Can't remember if the varnish was Maimeri brand or another, but Blick would know. Presumably that varnish works very well with gouache.

12-23-2017, 07:46 PM
There's a set of 8 colors on this Maimeri site shown that includes a bottle of charcoal fixative, apparently to protect the under-drawing from painting over with gouache. It's a curious thing, in my mind, to include with paint, but could be useful. Fixative is not intended to be used as a varnish.


Also, anyone using a tube of paint that is made of fugitive pigment should switch to another brand that uses permanent color.