Friday, March 22, 2019

Your Questions About Gouache

You had some questions on YouTube and Instagram:

Preston asks: Hey James, I want to start painting gouache en plein air. However, I’ve been having some trouble with the colors. I have experience oil painting, but all these gouache colors confuses me. There’s like 3 different types of reds such as “Spectrum Red, Primary Red, and Designer Red”, yet they all look like the same hue. Perhaps they have varying opacities? I plan on just buying Red, Blue, and Yellow with White and Black, and a few Earth Tones. I also plan on building the painting setup you discussed on your blog.

Gurney answers:  I would suggest buying gouache with well-known pigments, such as cadmium red, and avoiding colors with descriptive names like "spectrum red." As you probably know from your oil paints, the pigments are identified by Color Index Names (so cadmium red is PR108), and the reputable brands list pigments on the tubes. There's a website that tells you the pigment numbers. The opacity varies according to the pigment, and in my opinion, it's good to have some gouache pigments that are less opaque to use like watercolor in the lay-in stages.

Gouache is often marketed with "primary colors" or "spectrum colors" because it's so often used in art classes for painting color wheels. I would also beware of the cheap gouache sets that have weak pigment loads or pigments that aren't lightfast.


By the way, here's an interesting video about color pigments. (Link to YouTube)

Brady asks: "I was wondering how you frame a gouache painting once you have completed it. For example, a painting that you finish for a client or plan to put in an art show."

Gurney answers: I would mat and frame your gouache behind glass. You have to protect that delicate surface, because a splash of water, a sneeze, or an oily touch would spoil it. You could use a thin wood or metal photo frame and a generous mat to make the frame look museum-quality. It is possible to varnish gouache and treat it like an oil, but not really recommended, because the beauty of gouache is that matte surface, and a varnish will bring out lots of surprising layers. As always, experiment first!

Jonathan asks: What did you use to tone the paper tan?

Gurney answers: I toned the paper with a thin layer of casein paint (white, yellow ochre, and light red), but you could use Acryla Gouache or tinted gesso, or even brown India ink.

Tom asks: When working with gouache, or casein for that matter, do you wait a little while before folding up the sketchbook to avoid smudging, or does the paint dry sufficiently to allow you to pack up almost immediately? 

Gurney answers: It dries almost immediately (unless it's raining and 100% humidity), so I can pack i it up immediately.




9 comments:

  1. Is there anything you can add to gouache to give it the properties of acryla gouache?
    I had this one gouache color I wanted to use in an acryla painting, but I didn't want to smear it by accident later.

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  2. Scotty, yes, just mix it with a little acrylic polymer medium. That will do the trick.

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  3. James, thanks for posting the link to the Pigment Database - very helpful! It solved one of my weekly problems that arose when using Acryla Gouache: which colour of the range was closest to Pthalo blue. (Cobalt and cerulean, as there is no full pigment Pthalo from what I can tell.)

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  4. That video was fascinating! Thanks!

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  5. I thought it was a joke when you said in the color index of Color and Light that mummy brown was discontinued "not for a lack of mummies but for fear of illness", but now this video taught me that it really was made of mummies

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  6. PanSpec, M. Graham has an excellent line of gouache colours and it includes a Phthalo Blue (PB15:3).

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  7. Glenn, thanks for your answer. I do have Pthalo in my gouache lines, but I've been using Holbein acryla gouache for the last while because of how well I can glaze with it without worrying at all about the underlying layers. Holbein's line lacks a true pthalo blue, but several of their blues have pthalo pigment in different concentrations - with access to the paint I have, getting a good rich, dark/deep blue without resorting to black was a headache, without going to dark greens.

    I haven't experimented with using matte medium with regular gouache yet, though, so that might be an alternative, since its easier to get the correct pigments than with Acryla gouache.

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  8. Hello James Gurney, I was wonder since you spoke about framing under glass to protect the work. What do you do with the gouache paintings in the sketchbook, how do you protect and preserve them? I also notice you rarely paint on both side pages of a open book, I tend to paint on every page and wonder if this was a good or bad idea for gouache and watercolor? Appreciate all that you do.

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  9. Hi, I would recommend UV-filtering glass when framing a gouache painting, with a mat to keep the glass from making contact with the art. Display the art away from direct sunlight.

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