Thursday, August 29, 2019

What's the difference between watercolor and gouache?

A question that came up during yesterday's live video is this: How is tube watercolor different from tube gouache? 

Obviously they have similarities—they both have gum arabic binder, they're both rich and concentrated in their pigment loads, and they can be used either transparently or opaquely depending on the properties of each pigment. 

Is gouache always more opaque than watercolor? Is the pigment / binder ratio different? Is it supposed to be more matte when it dries?

To help shed light on these subjects, I asked two manufacturer's representatives to comment: Ann McCarthy of Winsor and Newton's Support Team, and Timothy Hopper, Executive VP of Holbein, Inc. 

1. Gurney: What's the difference between gouache and watercolor in their tube form?

Winsor and Newton: “Watercolor and gouache are similar in that they both are made with gum arabic binders. Designers gouache is considerably more opaque and this is done by loading additional pigment. While most colors in gouache are opaque, some colors, mostly transparent pigments, are semi opaque. 

"The artist doesn't generally need to add white to most gouache colors to achieve opacity. The only caveats would be that gouache is susceptible to cracking when applied too thickly and that both types of media remain soluble even when dry, so layering can be difficult and we don't recommend varnishing."

Holbein, Inc: “The principal difference between Artist Watercolor (WC) and Designers Gouache (GC) is: Watercolor (WC) contains less pigment and more Gum Arabic, and Gouache (GC) contains more pigments and less Gum Arabic. As you know we (Holbein) are not adding any whitening agent to (GC) but we specifically choose (GC) pigments that are naturally matte.

2. Gurney: Is it advisable from your perspective if people use gouache as if it were watercolor (namely, in a transparent fashion), and watercolor in a gouache-like way, adding white to get opaque passages? 

Winsor and Newton: “Watercolors are a traditionally transparent medium and usually applied in thin washes while gouache will be used when a more opaque color is desired. I suppose you could use them in ways they weren't intended for but it seems like a lot of additional work to turn a watercolor into a gouache and vice versa."

Holbein, Inc: If you add White to WC, it becomes opaque but your resulting color will become grayish in color."

3. Gurney: Is there any problem with using them together in the same painting?

Winsor and Newton: “Yes, they can be be used together."

Holbein, Inc: “It is common that WC and Gouache are mixed and used together in the same painting without any issue."

4. Gurney: Why is there a price difference between the two for the same pigment and same size tube?

Winsor and Newton: "Watercolor formulations are much more complex and cost more to make."

Holbein, Inc: “There has always been a price differentials between both gouache and watercolor. One of the main reasons is the production of Artist Watercolor is more detailed in nature than the production of Gouache. The same differential can be found in many high quality art lines."
Thanks to Mr. Hopper and Ms. McCarthy.
Amazon links:
Holbein gouache set
Shinhan Pass watercolor/gouache hybrid set

Gouache Ingredients: Info from Manufacturers
Gouache: Tubes or Pans?


Sheridan said...

The basic difference between watercolor and gouache is that the watercolor painting relies on a pure white ground to achieve the brilliance and luminosity of the pigment, which is basically a stain on the surface, and the gouache paint does not. The brilliance of gouache is achieved through the actual layer of the paint itself. Gouache paintings can be done on a toned ground, as you have often demonstrated in your videos.

I noted both manufacturers called them DESIGNERS gouache. My thinking on the title is that originally they were created for commercial work where bright colors would be used more often. Some pigments were fugitive, because the work was to be photographed for reproduction, and then discarded. I'm guessing they don't use fugitive pigments now, but that would have been a good question to have answered.

I have been using designers gouache for over 54 years. I only painted on illustration board, or 90lb watercolor paper that had been stretched, and glued to masonite to create a rigid surface. Only started painting on paper after seeing your videos. I wouldn' have thought they would hold up without cracking. I now have several pads of 80lb drawing paper, a few as large as 11"X14" full of paintings. I don't notice any deterioration of the paint film, and they have been flipped thru several times.
I do agree with the manufacturer, and do not recommend varnishing them EVER. I lost several paintings years ago (the ones on masonite) because they were varnished. I think it is because the varnish shrinks with age, and crumbles the gouache off the surface.

Watched the live video. Really nice to hear your thought process. Thanks.

Stephen and Nyree said...

This is fantastic information. Thank you for doing the research and sharing with us. I often mix W&N white gouache with W&N watercolors for opaque passages or entire sketches. This was enlightening. I struggle sometimes with the "graying" of some colors but I find ways to compensate. I learned from your Q&A and wanted to thank you for answering all those questions as well. It helps me see the mechanics of the process and hopefully find better results in my own efforts.

Pyracantha said...

Some of the Holbein designers' gouache are made with acrylic binder - Holbein's "Acryla" gouache. The acrylic dries to a permanent matte surface that will not melt under extra water. It's great.

Also, what is "bodycolor?" I see the word used in descriptions of 19th century British watercolors. What body is it? Is bodycolor a term for gouache used as semi-transparent wash and details?

Bells said...

I wish Have money... So i'm practicing with faber castell normal watercolor pencils... I use brushes with them, well someday maybe I will have it, I Will never Give up :) You give me hope, ty!

Stephen and Nyree said...

Pyracantha- "bodycolor" in those old English texts is Zinc White or Chinese White gouache.

I have read several old English texts on watercolor over the last two years and another common device was to dilute Sepia ink or India ink into three washes. One was very light, one was medium, and one was a darker wash. This would be used to create your first washes for shade or dark passages. Once this dried completely the watercolor washes would be added. Then once that was dry they would hit the accents or changes with "bodycolor." Mixing "bodycolor" with your tints of watercolor also seemed rather common for flatter matte passages where the luminosity was less important.

I hope that helps.

jeff said...

Thank you James for reaching out to the companies for the info.

Penny Taylor said...

I had so much fun watching the live gouache presentation. Thank you.

Gene Fama said...

That comment about how gouache picks up when you layer it makes me wonder why anyone uses artist’s gouache when acrylic-gouache solves this problem. Mr. Gurney, are there different situations where you prefer one over the other and is there a reason not to just use acryla-gouache for everything?

James Gurney said...

Gene, it's a good question. Most of the time I like having the paint surface remain open to later working because it means I can soften an edge after the paint has dried. That's a valuable thing with any opaque water medium because there's a tendency for all the edges to be too sharp.

Ted B. said...

I think bodycolor refers to paint straight from the tube or at tube-strength, mixed to the desired color...but not diluted with water into a wash. With pan paints, re-wetted into a paste with minimal water to be thick and opaque. Some might call it dry-brush.

Unknown said...

James, thank you!
I have a question about gouache lightfastness. Do you pay attention to the lightfastness when you pick your colors? I have just bought 24 colors Holbein gouache set. Most of the paints in the set have a 2 or less lightfastness rating. Is a rating of 2 which means "Moderately durable colors" according to Holbein acceptable for artists? (see Do you paint with such colors?