finishing a live sized painting in gouache

[Zaknafain]

I'm planning a portrait series in gouache since this seems to be my new medium of choice. Problem I only used it for small and quick sketches but I want to use it for a finished (25 h) live sized portrait painting (~1m²), and I'm not sure if gouache is the right medium for it:

My first question is: what should I paint on? Canvas probably won't work for gouache, and paper seems to be an odd choice for this size. Also most watercolorpaper is taking damage if you work on it for to long.

You don't get to see many livesized paintings in gouache, which makes me wonder if there are other technical issues I will have to face for this project. For example I heard if you work in to many layers with gouache it will get brittle and cracks might appear.

From my own experience I know that after working on a painting for a certain time, blending with a wet brush will become pretty unpredictable due to the amount of paint underneath thats bleeding through. I know there are ways of fixing the paint, but can I still work on top of that?

[dbclemons]

No, gouache paint is not designed for painting thickly or on a surface that can flex or move like stretched canvas.

Paper is an ideal surface for gouache, and larger sizes in rolls are available if you hunt them down. Heavyweight watercolor paper is not easily damaged, but at that size will need a firm backing support.

A traditional gesso ground works well with gouache, but at that size takes some effort to apply properly. There are acrylic primers on the market that are more porous than usual primers, and are about as absorbant as paper. They work okay with gouache. Golden, Matisse, and Art Spectrum have a line of these. Fredrix also sells a watercolor canvas (http://www.taramaterials.com/ArtistCanvas/ProductCategory.aspx?path=005009005) that has a similar coating.

[Mirana]

Geez, I can't imagine the cost of using that much gouache. That's dedication.

[Zaknafain]

thanks a lot, now I have another question:
can I paint with gouache on top of thin layers of acrylics?
That way I could do the whole underpainting with acrylics (saves a lot of paint) and still have the ability to blend the colors in the finishing stages after I switched to gouache.
will this result in adhesion problems?

[Grendel Grack]

I think that you might encounter adhesion problems with this applilcation. If you plan to use thin layers of acrylic, try it on an unprimed absorbent surface like 300lb watercolor paper or illustration board. That way, the acrylic will absorb a bit into the paper and will leave more "tooth" for the gouache to adhere to. Try a small sample and see how it works.

In regards to the size/support issue, try mounting watercolor paper to hardboard. This will give you the absorbent surface you need yet also provide rigidity to prevent the gouache from cracking. Todd Lockwood (http://www.toddlockwood.com/faq.shtml#what_surface) has a tutorial about how he mounts his own paper at his website. Your process won't need to be the same as his (he uses oil), but the initial steps he describes are helpful.

[arttorney]

How long are these to last? "The book" says that a lot of gouache brands use colors that are not necessarily light fast. Watercolors have a better reputation (and tempera for that matter).

Maybe you would need to sand lightly on your acrylic surface to get gouache to stay where you put it.

[entdroid]

thanks a lot, now I have another question:
can I paint with gouache on top of thin layers of acrylics?
That way I could do the whole underpainting with acrylics (saves a lot of paint) and still have the ability to blend the colors in the finishing stages after I switched to gouache.
will this result in adhesion problems?

Well, I say you try that in a small piece of paper, but I don't think there should be much of a problem, Fed has done that in some of his works (not in such huge painting though) and it worked fine. But you could always give it a hand of matte medium before applying the gouache if you're unsure. Or you can try vinylic gouache (such as Flashe (http://www.dickblick.com/zz006/97/)) for underpainting, the finish is pretty much like gouache so it's matte, quite opaque and has a lot of tooth, but it lacks the blending quality of gouache because it dries fast and permanently like acrylics.

[Grendel Grack]

How long are these to last? "The book" says that a lot of gouache brands use colors that are not necessarily light fast. Watercolors have a better reputation (and tempera for that matter).


There are some pigments that are more fugitive than others - this is true for any paint media. Any student grade or low quality paint will have very low permanence ratings. If you purchase a professional grade paint such as Holbein or Winsor Newton, the permanence information will be listed on the tube. Many professional paints use modern pigments which are more lightfast or permanent compared to their traditional counterparts. It has nothing to do with one media being more lightfast over the other.

[arttorney]

I'm not talking about differences between distemper or egg or water. I'm talking about gouache being viewed by its makers as a medium used by design people who promptly image the original and then don't worry about the original any more, possibly leading to a usage of more suspect pigments.

I have Winsor & Newton gouache but I couldn't find anything on my tubes to set my mind at ease about permanence. I just assume the worst if I don't see "Artist Quality" or preferably Permanence Code information prominently displayed on the tubes. They do it with the oils.

Then again, most of the ready made tempera I've seen looks like it was made for first graders, so I already don't believe everything my Artist's Manual tells me. Just babbling, I suppose.

[Grendel Grack]

Illustrators and designers have begun to care about the longevity of their work and many companies have endeavored to achieve higher lightfastness ratings for their watercolor/gouache lines. Many of the paints in the Winsor Newton line have a permanency rating of "AA" or "A". Here is a chart (http://www.winsornewton.com/products/gouache/designers-gouache/composition--permanence/) from their website.

If you can't find any info on the tubes, chances are that the company's website will list the info. After all, there is only so much room on those tiny tube labels. Some of the brighter color are very fugitive. My favorite, Alizarin Crimson, has a horrible rating but the color is so awesome and Permanent Alizarin is just not the same. So, I just make sure to treat those pieces made with that color with great care. When not on display I store them in archival envelopes inside a portfolio so they won't be exposed to light. When they are on display, I frame them with UV blocking glass.

[peterworsley]

I have painted many large paintings in gouache, though today I mostly work in oil.

See my online article on Gouache Painting:
[URL="http://www.peterworsley.com/Gouache.html"]

I would recommend you using clayboard or watercolor canvas panels. The canvas panel have the advantage of lightness, but do not support thick painting as well as the clayboard.

[dbclemons]

Sorry. Double post. -

[dbclemons]

...I'm talking about gouache being viewed by its makers as a medium used by design people who promptly image the original and then don't worry about the original any more, possibly leading to a usage of more suspect pigments...

Not all of them are "designer" label. There are different brands that use a high quality mixture in their paints, such as Schminke Horadam or M. Graham. These are much like watercolor but with a high pigment load and larger pigment size so that they can be used opaquely.

Mirana makes a good point about using that much gouache, since almost all brands come in small tubes. DaVinci makes a decent gouache that comes in 37 ml tubes and might be a better choice for that much painting.

You could paint gouache over thin acrylic washes, but it won't adhere as well. Another option is to use acrylic "gouache" which is an acrylic polymer based paint that handles like genuine gouache but dries permanent.

...I would recommend you using clayboard or watercolor canvas panels...

Ampersand's Aquabord (clayboard textured) is a good surface for gouache. I think the largest size is 16 x 20." The watercolor canvas come in rolls that is about 5' wide by several yards long. It would need to be mounted to a firm backing like hardboard for gouache.