EDIT: For those interested in learning more about gouache resist, there's a more up to date look at the process in the post Gouache Resist, Part Deux.


First, get the materials you will need together.



White Gouache: The tubed variety seems to work best.

India Ink: Any really black ink that is labeled as "waterproof". This is important since this method involves washing away the gouache and leaving behind the ink. Avoid "acrylic" ink. I recently used it on one of my experiments with less than desirable results.

Paper: Heavy paper to be precise. Watercolor paper will work best. Anything that will not deteriorate while being doused with water. This means printer paper is out.

An assortment of brushes: One to apply the gouache and one to apply the ink (a large flat brush).

Other things: A pencil to draw your design, a dish to hold your paint and ink, a water supply to rinse your brushes, a sink to rinse your piece in. Large cup of coffee optional but recommended. Ample amount of time and patients necessary.

Let's begin!

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Step One: Draw your design.

Make it light, and fairly simple to start out with.



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Step Two: Paint!

This is the tricky part, and where you need to understand how gouache resist works.

The way this technique works is by laying down a substantial layer of gouache paint onto paper. What the gouache does is create a barrier between the paper and the layers of pigment above it. Once the gouanche is dry, a layer of waterproof ink is put over it and allowed to dry thoroughly. When the surface is sprayed with water, the gouache under the ink lifts and takes the ink above it with it, leaving every part of the paper that was painted with gouache white. Neat huh?

Anyway, on to the painting. Decide what you want to white in your design, and what you want to be black. Keep in mind that whatever you want white will have to be painted with the gouache. This makes doing your traditional black lines on white paper a tricky task. You may want to start out doing a negative for your first try (painting your lines in white and leaving the negative space black), or stick to simple black and white shapes and masses (no lines).



Another issue you will encounter is how hard it is to see what you are painting since it's white gouache on white paper. Tilting my paper helps me see what I've painted and what I haven't, and having good lighting is key. You can also hold it up to a light source or work over a lightbox to see what parts are more opaque than others. Tinting the gouache with just a little bit of a non-staining/tinting watercolor paint also helps.

Your gouache needs to be a fairly thick soupy consistency. Don't be tempted to water it down too much, or else your ink might go through to your paper and you'll have problems lifting it from the paper.

Allow your piece to dry completely. This shouldn't take too long since gouache dries pretty fast.



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Step Three: Ink!

This is another tricky part. A substantial layer of ink needs to be applied over the whole area (all the places you want black to show up). The problem arises to gouache's fickle nature... the gouach will want to lift and start to dissolve when the ink is added over it. You want to avoid going over the same spots twice to prevent the gouache from washing away too soon. Make sure you have enough on your brush to cover a specific area without having to go back over it.

It's also worthy of noting that you don't what overly saturated areas of ink, or big puddles forming. It takes longer for the ink to dry and it'll have the tendency to flake off. Do this on a flat even surface.





Let your ink dry COMPLETELY! This is the worst part, in my opinions. Waiting for ink to dry is tough. But it's worth the wait, trust me. Depending on how big your piece is and how much ink you used, it could take up to an hour for all areas to be dry to the touch. I recommend waiting longer though, at least a few hours. I never take my own advice though, so i went ahead anyway...

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Step Four: Rinse!

This is my favorite part. This is where all your work comes to a head and you can finally see how good of a job you've done.

Once your ink has dried, take your page to the sink and stick it under running water. The gouache will begin to lift and your design will slowly appear. The more stubborn areas can be gently rubbed with a soft brush to encourage the gouache to separate from the paper. Don't be tempted to rub too hard (like me) if some areas don't come off.







Once your image has materialized, lay it down on some paper towels and pat to remove moisture. Allow to dry flat (if your paper does not dry flat, press it under a pile of books for a day or so)

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Viola!



My sample image didn't come out the way I hoped, but that's kind of the fun thing about this technique. As much as you want to control how the image will come out, It'll always surprise you.

I recently learned that this same technique can be used using colored gouache, which makes it much easier for you to paint your design. I haven't tried it yet, but you can bet your bottom dollar I soon will.

Here are some other example of gouache resist I found on the web:

http://www.willgoh.com/Gastronomy/Gastronomy.html
http://www.kenaustinartist.com/page/page/1669143.htm