For this example, I prepped Winsor & Newton's Designers Gouache in Primary Blue. However, I typically use the less expensive Artist's Loft Gouache for practicing or personal projects. It works well and won't break the bank.
Step One: Assemble Supplies
When prepping gouache, you will need a small, deep container in which to mix, use, and store unused paint. I used a paint cup--about 3.5 oz in volume and about an inch deep--with a storage lid. I recommend using a small cup like this for a couple reasons. One, if your cup is too big, you will have either too-watery gouache or too much mixture, and to start, you don't need a lot of gouache mixture. Two, if your container is too shallow, you won't be able to properly dip and load your calligraphy nib.
You definitely don't have to buy paint cups to mix your gouache. You can use something small you have at home, like an empty Carmex lip balm jar. However, it is nice to have a container with a lid so you can store any unused mix until you're ready to letter again.
You will also need water, a small paintbrush for mixing (I prefer one with firm bristles), a paper towel for spills and cleaning, and either an eye dropper or straw for adding the water to the paint cup. (Or you can just stand at the sink and use a very fine trickle of water, but start the flow before putting the cup underneath.)
Step Two: Place Gouache in Cup
Measuring out the gouache is a process of estimation. When I first learned how to prep gouache, the instructor showed us a swirl of the paint in the cup and said that was how much we should add. My advice for first timers, start small. You can always add a little more if your mixture is too thin. I usually add about a "loop" of paint, as shown below.
Side note: If I'm mixing different colors to create a custom shade, this is the point in the process where I do it. I typically will add a few small dollops of each color and blend with a paintbrush. When I reach the desired shade, I move on to step three. Keep in mind that the water will slightly lighten whatever color you use.
Step Three: Add Water to Cup
Use your eye dropper or straw to fill the cup 1/2 way to 3/4 of the way with water. Again, if this is your first time, you can start with less and add more as needed.
Step Four: Mix Gouache and Water with Paintbrush
Use the paintbrush to mix the gouache and water together, pressing down and stirring in a circular motion. Periodically you can pull the brush out to see if gouache is clinging to it. If it is, slide the brush over the rim of the cup to scrape the gouache off and continue mixing. Make sure to press the bristles into the edges where the bottom and sides of the cup meet as the gouache may gather there. The goal is to blend all the solid pieces of gouache into the water.
Your gouache is properly mixed when it is fully blended with the water and the consistency is similar to milk. This is a good consistency for calligraphy. It's a little thicker and remains on the nib. When I do brush lettering, I usually delude the mixture with more water.
Step Five: Store Unused Mixture
The great part about using a cup with a lid is that it's super easy to store your mixture, or take it on-the-go. If your mixture has been sitting for a little while, the gouache may begin to separate somewhat and settle at the bottom. Before you use it again, mix it up with your paintbrush. If it's getting stringy or solid, it's time to dump it and make some fresh!
If you have any questions about gouache prep, please leave them in the comments or tweet to me @MrsEliseMance. Next I will be covering some lettering techniques using prepped gouache so stay tuned!
