Tuesday, June 23, 2015

Gouache Ingredients: Info from Manufacturers

Top: Winsor Newton, Second: Acryla Gouache (Holbein),
Third: Holbein Gouache, Fourth: M. Graham,
Fifth: Utrecht (left), Daler Rowney (right)
To research the gouache video, I decided to ask manufacturers what ingredients they put in their paints. Here's what I wrote to them:

Dear _______,
I’m currently working on a new instructional DVD called "Gouache in the Wild," and I had a question.

In my research about gouache paints, I'm encountering some confusing information about the formulation of gouache. Many manufacturers claim in their advertising they use no opacifiers, chalks, fillers or other agents or "so-called adulterants" added to the pigment and binder, giving the impression that gouache is made up of solely of pure concentrated pigment and gum arabic. With an opaque pigment such as Venetian red, I can imagine that such a formulation might be possible.

But according to other information I've found, some pigments are so transparent (such as phthalocyanine and other organic pigments) that even if they are used generously in the formulation, the gouache would be unacceptably transparent and dark, and therefore whiteners or opacifiers are used to make them lighter in value and more opaque.

Other authorities claim that the formulations include other necessary ingredients such as honey, plasticizers (glycerin and/or dextrin), and preservatives to protect from spoilage or to improve the flow characteristics.

Could you please comment on what ingredients go into your gouache?

Sincerely, James Gurney

Top: transparency test, bottom: value shift test
None of the companies paid me anything or asked for any kind of special favor. But they all gave me thoughtful answers. Here's what I heard back:

Holbein

"You are correct, there is so much differing information on Gouache from manufacturer to manufacturer. Here is what my understanding is with respect to competitive Gouache lines and what Holbein has always offered on theirs.

"- Almost every gouache line, regardless of origin, contains typically either talc, marble dust, Calcium Carbonate or titanium dioxide. It is very easy to tell when using a gouache that contains these ingredients. The colors tend to be drab and every color will have a chalky/milky overtone.

"- Holbein does not add any of these ingredients. Typically they achieve opacity through pigmentation. Holbein gouache is therefore slightly less opaque than other gouache lines, but offers superior color saturation, handling qualities and all colors lack that chalky/milky look. Holbein uses a moisturizer, Polyethlene Glycol and a preservative, benzisothiazoline.

"- Holbein acryla gouache uses a pure acryl resin as its base.
I hope this helps and please let me know if you have other questions."

All the best,
Timothy S. Hopper
Executive Vice President
Holbein North America

More product information on Amazon: Holbein Acryla Gouache


Winsor Newton
"Great question! In fact, gouache can be rendered opaque through two different formulation approaches. The first, and most commonly used, is through the addition of opacifiers like calcium carbonate or titanium dioxide or other things. The result is greater opacity, but the clarity and intensity of the color is compromised, sometimes quite appreciably.

"The other approach is to use pigments that tend to be naturally opaque and to load the formulation so heavily with pigment that opacity is the result. Of the two approaches, the second is the one we use. The opacity really and truly comes just from the pigment load.

"I would also like to tell you how much I enjoy your book, 'Color & Light'. I teach and recommend it to all of my students. It is the best book on the subject I have seen. It is a great book! I wrote a book for North Light about twelve years ago. 'Colour Secrets for Glowing Oil Paintings' so I can appreciate the amount to time and work it takes."

Best wishes.
Doug Purdon
Technical Advisor
P.S. I just received this reply from our technical manager.
Some opacifier is added, but the formulations rely predominantly on being heavily pigmented.
I suspect that when the pigments are very transparent such as Pthalo Green or Blue this would be necessary to ensure that they had sufficient covering power. 

More product info at Amazon: Winsor and Newton Designers' Gouache

Utrecht
"Historically, Utrecht paints have been formulated with heavy emphasis on single-pigment colors to deliver the unique characteristics of the high quality raw ingredients we use, and this is still true of our Designer's Gouache line. Consistent with this goal, we use opacifiers and matting agents only where needed, in the minimum effective proportion. Depending on the individual color, we may use inert pigments like blanc fixe or barium sulfate to achieve an opaque, matte appearance.

"A few including Cadmium Lemon Yellow, Cobalt Blue Hue and Naples Yellow have a small amount of titanium white added, either to achieve a hue consistent with a traditional color or to bring a pigment to its best advantage. More information about pigment content is included on the product MSDS:http://images.utrechtart.com/Content/MSDS/UT-Designers-Gouache-13.pdf

"Our objective was to offer designer's gouache worthy of the fine artist's palette, something that would never be called "chalky". There may be more variation in opacity/transparency across our assortment than with some brands, but that's a deliberate choice we think makes Utrecht Gouache such an excellent paint. Since skillful and sensitive use of white is so important in gouache painting, we feel that producing tints is best done on the palette by the artist. After all, you can always add white, but you can't subtract it.

"The binder for Utrecht Designer's Gouache is pure gum arabic. We do add antimicrobials, wetting agents and plasticizers. Our approach is to develop each color individually rather than a generic palette, so there is no overall single formula for any of our professional paint assortments. I will have to consult our Brand Manager to find out which colors include specific agents. None of the colors in our gouache line include ox gall. I'll review my archives and see what other information I can discover. Thanks for your interest in Utrecht paints!"

Matthew Kinsey
Utrecht Art Supplies


M Graham 
"Thanks for asking. As a small child I wanted to be either a ballerina or an archaeologist so I have been fascinated with Dinotopia for years. Never occurred to me that I would be a paint maker.

"When we looked at entering the gouache market, many products were termed "designers" gouache. The idea was to make a design, take a photo and throw the original art work away. Many of the colors were fluorescent or not lightfast because the work was "swimsuit fashion" and permanency did not matter.

"We decided to go with a "fine art" version instead. We use the same pigments as our oil, acrylic and watercolors so there are some that are so transparent that opacity requires whiteners. Instead of formulating with opacifiers or whiteners, we leave this decision to the artist. Or the color can be diluted all the way to a wash without chalkiness.

"Since our whole operation is 9 folks and a part time stray cat in a 3000 sq. foot cinderblock building surround by hops fields in rural Oregon, we do not go much farther in discussing our formulations."

Diana Graham

More info on Amazon: M. Graham Gouache Set

Caran d’Ache
"Acrylic, watercolor and gouache are waterbased paints. Acrylic is resin based and watercolor and gouache are gum based (resin is not watersoluble, reason why you can’t solve acrylic after it has been dried) and gums are watersoluble.

"Watercolor is transparent, reason why there is no filler in the composition. It is just a big amount of pigment ground in an excellent gum like arabic, or better, traganth gum.

"Gouache and Acrylic are opaque by definition, reason why they contain calcium carbonate to give them opacity. The binder used for gouache is often potatoe starch (dextrin) but it can be also arabic gum in case of extra fine gouache.

"Sometimes, pigments are opaque enough not to be mixed with calcium carbonate (chalk). It is more in the case of mineral pigments like iron oxides or earth (like sienna, umbers etc..).

"Hope you will find answers to your questions."

Regards
Eric Vitus
Fine Arts Manager
CARAN D'ACHE SA

More info on Amazon: Caran d'Ache Gouache

Richeson
"We have never manufactured gouache, so I am very short on knowledge. In general, most gouache today, particularly at lower quality levels (tempera paint) will contain chalk, because it makes for great opacity and is a cheap filler."

"For more expensive lines of gouache, it seems to me that it’s not likely/possible that something is not being added. For example, Ultramarine blue is a transparent blue, but shows up in a gouache line as opaque. This suggests that something has been added. There are opacifying pigments (don’t quote me on the correct terminology), really just additives meant to provide certain properties to paints that can be added. I suspect that while they are not adding Chalk, they are likely adding these opacifying “pigments”. Now for you and me, a pigment should be definable as a color of some sort. The opacifying pigments I know would not make any sort of recognizable paint."

I hope this helps.

Darren Richeson
President
Jack Richeson and Co., Inc

Other brands
Shinhan Pass makes a 48-tube set of "hybrid" gouache/watercolor paints. They're pigment-rich, non-toxic, and use gum arabic as the binder and most of the colors can be used transparently or opaquely. But note that 8 of the 48 colors are not lightfast pigments, so they're better for designers or sketchers than gallery artists. The set is priced around $180, not bad considering they're 20ml tubes, while most other brands are 15ml.

These are other brands that I either overlooked or wasn't able to connect with. 
Lukas Gouache
Schmincke Horadam Gouache
Pebeo Gouache (I got a set of these in Australia and used them to paint the comp for the dino stamps)
---
Own the 72-minute feature "Gouache in the Wild"
• HD MP4 Download at Gumroad $14.95
• or HD MP4 Download at Sellfy (for Paypal customers) $14.95
• DVD at Purchase at Kunaki.com (Region 1 encoded NTSC video) $24.50

22 comments:

Andrew said...

Ah, this is great stuff - it's always wonderful whenever manufacturers are willing to talk somewhat openly about their manufacturing and the science behind having to make these paints.

Your image of the swatch tests though brought up another question in my mind - What brands have you found to have the least amount of value shift between their wet and dry states? From what it looks like Utrecht and M. Graham seem to hold their own quite well in that category. I've been using Da Vinci gouache recently and even though the consistency is quite nice right out of the tube, I've noticed at least with greyscale swatches it'll have a noticeable shift - often up to two value steps above or below the wet state once it dries.

James Gurney said...

Andrew, some gouache manufacturers advertise their paints as not shifting in value as they dry (notably Holbein's Acryla Gouache). But in my experience, all matte (ie non-glossy) paints will shift somewhat from their wet to dry states. The effect is more pronounced in the dark valued paints. Very light paints sometimes darken a little as they dry.

As I understand it's an inevitable property of the paint changing from a relatively specular to relatively diffuse reflective surface. In other words, the light bounces off the wet paint like a mirror, but when it dries, a ray of light hits the surface and bounces in all directions. This extra diffuse reflection is what makes the dry paint lighter.

I've kind of gotten used to value shifting, and it's not much of a problem unless you need to match a big flat area or a paint swatch.

Samuli S. said...

I'm a bit surprised by the exclusion of Schminke from the list. Is Horadam gouache rare in the US, because it's pretty ubiqutous in Europe. I am interested in the qualities because it is also the only artist grade paint available locally.

Just finished watching Gouache in the Wild and it was very enlightening. I've been struggling with the transition from watercolour to gouache and the video is a superb help.

Martha said...

Fascinating--thank you!

Andrew said...

I suspected as much, especially because I've heard people talk about putting a final varnish over an oil painting to "deepen the darks," so it makes sense it's just a matter of gloss vs matte finish in the paint. If anything, at least it forces you to train up your eye to predict and see what the values and hues will be. Thank you so much for the info though, James!

HNK said...

What do you think about Schmincke Gouache?

Tom Hart said...

This is wonderful information, James. Thanks for it! Are you comfortable sharing your personal brand preference(s)? (Undestandably, it might not be the same for all colors...)

Ann Malmlund said...

Thank you for all the information. I bought your film and enjoyed it very much. I have one comment to add about a technique I have not yet seen mentioned anywhere. I find that the Naples Yellow offered in the casein line of paints is far from true to color being more like a lemon yellow. Since I prefer to paint in casein and use a lot of this color I now use Winsor Newton Gouache Naples Yellow and mix it in with the casein. So far this has worked very well for me.

James Gurney said...

Samuli and HNK: I've added to the end of the post a few other brands that I either overlooked or wasn't able to write to, including:
Lukas Gouache
Schmincke Horadam Gouache
Pebeo Gouache (I got a set of these in Australia and used them to paint the comp for the dino stamps)
Van Gogh Acrylic Gouache
Turner Acrylic Gouache

Tom, I'm not ready to recommend any particular brand or rate them because I haven't used them enough. However, I will say that I use Schmincke watercolor and I love them.

Samuli S. said...

Thank you for the update!

Carole Pivarnik said...

This was great info. Thank you for doing all this research and sharing it with us. I was especially interested to find out about the size of the M. Graham operation...suddenly to support such a small business, the price of their paint seems completely reasonable! I just wish they'd sell it in larger tubes.

sketchbookblue said...

Just to add to the list of manufacturers.... please could you comment on Art Spectrum paints made here in Australia - I have a set of their gouache that I sometimes use over watercolour. Thanks alot for the detailed information.

Mustafa Umut Sarac said...

Hello there, Someone mentioned in above posts , high transparency of color layer , makes it darker looking. Can you comment on that ? Do you think less transparency of paint layer makes it more vivid and lively ? Thank you, Umut

James Gurney said...

Mustafa, good question. A more transparent pigment will generally look darker as it comes out of the tube because the light goes into the blob of paint and doesn't just bounce off the surface. But when you spread the paint out thin, it looks lighter. An opaque pigment can be either dark or light depending on the color. Transparent pigment is not necessarily more vivid and lively; it depends on the color and what it's doing. These things become clear as you experiment with the paints.

Carlos said...

James, I'm planning my first real attempt at gouache pretty soon, and I need to shop for supplies. What brands and more importantly what colors would you recommend for a 'starter set'? Is buying individual colors better as opposed to getting a boxed set? Would the same list from your Watercolor in the wild post apply here? Thanks, Carlos.

James Gurney said...

Carlos, I'd recommend the boxed set of regular gouache from Holbein. It's a good assortment of colors for a reasonable price. As you need to replace tubes, try other brands to see how you like them.

Catagonia7 said...

Can you set out the paints and let them dry, then rewet them?

thanks!

James Gurney said...

Catagonia7, you can in theory, but I find the paint is juicier and more abundant if I use it squeezed from tubes.

Catagonia7 said...

Thanks!

George Deep said...

I'm fairly new to using Gouache and was wondering if putting the tube Gouache into an empty travel tin like watercolors is okay to do? I know not with the Acrylic Gouache, but maybe with the "Designer" style gouache?

James Gurney said...

George, yes, you can do that because the binder of gouache is gum arabic, which is water soluble. Nathan Fowkes often uses his gouache this way. You can put a drop of water on each cake of gouache when you leave for your painting excursion to help begin to soften it up so that it's more ready when you get there.

Linda said...

I'm intrigued at the thought of a "part time stray cat". Does one have to go to Oregon to find such a critter?