Rewetting Gouache -- Tips and Tricks

A couple of my gouache (left) and watercolor (right) palettes with some little sketches.
The small, airtight plastic container has titanium white gouache in it.

Lately, many people are saying online that you cannot or should not rewet gouache after it has dried. But I've been rewetting gouache forever. That's why I love gouache as a travel medium. If you don't mind traveling with tubes of paint, and taking the time on location to set up your gouache palette, then just keep doing what you're doing and ignore this post! Personally, I want the advantages of oil or acrylic if I'm going the wet paint route. Gouache offers me portability and compact simplification when those are a priority, such as when out on location or working in a sketchbook. It does not have the feel of that luscious, smooth, wet paint out of the tube, but it serves my purposes.

(Note: "Acryla Gouache" is acrylic paint, not gouache. It cannot be rewet. This post applies only to gouache, which is opaque watercolor, and remains water soluble even after it has dried.)

If you've been struggling with rewetting your gouache, or the appearance of the rewet gouache on your painting, I have a few tips that may be helpful for you:



1. USE A PALETTE WITH HALF PANS. Skip the types of palettes that have the wider, shallower areas for the paint. The wider and shallower the paint holder, the faster your gouache will dry. When the dry gouache cracks (as it generally does), it will shift inside your paint palette due to the shallow paint recesses, and contaminate other colors. In short, it gets to be a real mess.

2. CARRY YOUR PALETTE UPRIGHT. With a half pan palette, it's really easy to keep the palette face up in your painting bag. Any cracked gouache will remain in the deep, walled pans where it belongs.

Distilled water, and the bottles I use to carry it with me.

3. USE ONLY DISTILLED WATER IN YOUR SPRAY BOTTLE, AND ALSO HAVE A DROPPER BOTTLE OF DISTILLED WATER WITH YOU. As an alternative, you can bring an eyedropper and a regular bottle of distilled water, in place of the dropper bottle. Use only this water to dilute your paints or spray them. Tap water, and even spring water, contain minerals that can affect the clarity of your paint over time. That might not happen the first or second time you rewet or spray them, but if you reuse your gouache as much as I do, eventually the deposits will affect your paint, just like they do your coffee maker. Distilled water maintains the color brilliance, since the minerals have been removed. (This applies to watercolor pans too.)

4. PREWET YOUR GOUACHE. I don't mean to spray it a few minutes before you start to paint; I mean the night before. If you forget, do it awhile before you leave the house to go paint. Spray the set with distilled water, and top off each pan with drops of distilled water as needed. Check it ten minutes later and add more distilled water if it has completely soaked in. Each color should look wet. Then pack it up so it will stay flat in your painting pack or bag. Spray with more distilled water out on location as needed.

5. DON'T LET WHITE GOUACHE MIX INTO OTHER PAN COLORS. It doesn't play nice. Nothing will suck the life out of your color chroma, or limit your ability to mix darks, more than titanium white gouache migrating into your colors. Mix tints in a separate area from darks. Wipe off and wash any brushes containing white before dipping into your colors, or or use a palette knife, or another brush. Keep a white pan for cool colors and a white pan for warm colors to help keep your whites from becoming grays. Add a small, airtight plastic container of fresh, titanium white gouache to your painting bag, in addition to the pans in your palette. Spray it with distilled water from time to time as needed to keep the fresh consistency inside the container. I use the little lid of that container as a tiny white palette, to get the pure white onto my brush in exactly the consistency I want. Avoid mixing colors into that container of wet, white gouache. Take some out with a palette knife or brush to put onto your palette mixing area with your pan set, if you find yourself in a situation where you need a lot of white.

Cotton rag paper from India

Recently, I got some colored sheets of handmade, cotton rag watercolor paper. It came in a package with 20, letter-size sheets -- two sheets each of 10 different colors. I thought it would be wonderful for mixed media and especially gouache, so I tried it out with some little paintings today. I absolutely love this paper. I don't remember who makes it; I lost the sheet with that information. I got it at the Rhinebeck Artist Shop in New Paltz, New York. It's a great store! They have most of my favorite art supplies, as well as some unusual things that I don't see in the online catalogs. It's nice to be able to browse art supplies in person, and also to support a great local art shop. They have stores in Rhinebeck, Kingston and New Paltz. Here's a link to their website.

[Edit: Many thanks to Kia, who identified this paper as Khadi. You can see her information about the paper down in the comments section.]

The little paintings were done with watercolor and gouache. You can see that I kept the pans of color pretty clean and tried not to let the white travel into pan colors. I generally save those small areas at the bottom of the palette for my white tints, saving the larger, upper areas for watery washes and darks. The grays on the right side of the palette are the Turner Design Gouache Neutral Grays. I like having them in my palette for quick value studies out on location, though I rarely use them for color mixing. Most of the other colors are other brands -- Winsor Newton, Holbein, DaVinci, etc. I use a lot of different brands when it comes to gouache, though I do have favorites for some colors.

I hope the tips above help some of you to travel more easily and set up faster with this versatile medium! Rewetting gouache may or may not suit the way you paint, so make up a small pan set to test drive how it works for you and paint brands/colors you like.

Megasketch Monday and More:  I'm sorry there was no Megasketch Monday post this week. After hurting my hand and not being able to type for a few days, I'm trying to evaluate whether or not the Megasketch posts are of enough value to my readers to warrant the work involved in photographing all those sketches and describing techniques, resources, and my thoughts along the way on a weekly basis. If I'm wrong about that, feel free to let me know. Hopefully, those of you who have taken on the project are well on your way, have determined your areas of focus, and formulated action plans that work for you. There will be at least a few more Megasketch Monday posts (which are already in progress), as well as more lightfastness tests coming, sketches from Maine, Mohonk, Mystic and other destinations, some reviews of brands of brushes and paints I've been test driving, sketchbook binding, and more. There is so much to the Megasketch project that I feel like I could easily post just about that for six months, but then I'd never have time to write about all those other things!