First and foremost, one of the most confusing things about gouache may be simply how to pronounce the word. It’s not “gotch-ee” or “gwachee” or “goo-ach-ee”. This strange little word is pronounced “gwash”. Yes, just adding the g sound before the word wash is pronouncing it correctly.
Now that we’ve gotten that out of the way, let’s talk about how and when to use gouache. Gouache is similar to watercolor in that it is not permanent and will move when wet. It differs because it contains more pigment and less binder than watercolor, and it is much more opaque. Most often, our customers use gouache when they have a less common color requested for wedding work. If you wanted to use gouache for a project, we’d highly suggest checking the permanency rating to ensure that you use colors less likely to fade over time. Some of the colors are considered fugitive, which means they can fade in just a few short months. Winsor and Newton uses a rating system of AA, A, B, and C with AA being most permanent and C being fugitive. M Graham Gouache uses a system of LF I to LF III with LF I being excellent and LF III being acceptable.
The other thing to keep in mind when using gouache is that due to less binder being present, gouache can crack if you do not mix it with enough water. Because you will need to thin it down enough to write with it, this is not generally a problem. However, if you wanted to use it to create a background, you would want to keep that in mind.
Gouache is very simple to use. Because we get so many questions about it, we thought it might be helpful to understand how to mix it. To get started, you’ll want a small mixing pan (or small storage bottle if you need to mix a larger amount), your tube of gouache, a dropper bottle filled with water, and a mixing brush.
First, drop a small amount of gouache into one of the small wells of your mixing pan. Do not attempt to fill the well; it will make your gouache far too thick to work with. The amount pictured here will give you plenty of writing fluid.
Next, add water, but do so slowly. Start with two-three drops, and mix it in completely. From there, add one-two drops at a time. By adding water slowly, you will be able to mix the gouache and water together better. Dropping a large amount of water on top of your gouache at one time makes it exceedingly difficult to mix. You’ll want to keep adding water until you get the gouache to a coffee creamer consistency.
To write with the gouache, you will brush it onto your nib with the same brush you used to mix it. It is not recommended to dip your nib into a small well; it ends up pretty messy, and the shallow nature of the well makes it difficult to pick up enough gouache. Flick your nib over a scratch sheet of paper and make a practice stroke before you begin lettering.
If the gouache is not flowing well, there are two things you can try. First, it may still be too thick. In that case, simply add more water. However, it may been too thin or may not adhere to the nib well (meaning it just falls or drips off). In that case, you can add a small amount of liquid gum arabic. A drop or two should be plenty!
Though the gouache lines we carry offer a wide array of colors, you may occasionally need to mix colors to get the right shade. In that case, always start with your lighter color and then add the darker to it. If you want a lighter shade of a color, mix up white and then add the color to it. If you want a darker shade, mix the color and then add black to it. If your colors are of equal shade, add the primary color to the secondary or tertiary color. Overall, we recommend mixing gouache with other gouache as opposed to mixing it with watercolor or ink. Some of our customers also like to add a little metal powder (like Schincke Tro-Col or Pearl Ex) to their gouache to give it a little sparkle. Others mix in a small amount of acrylic mediums to help improve the permanency of the gouache. (See Winsor and Newton’s instructions on how to do this for more information!)
Once you’ve mixed your gouache, you can store it in a sealed container. We even have customers who let it dry completely in their small pan wells and then wrap it with plastic wrap. (Just know that depending on the humidity in your area, leaving it in an open pan to dry can cause mold.) Reconstitute your gouache in jars by adding water as needed and mixing once again.