An opaque, vibrant, water-based paint, gouache is fantastic for mixing custom hues, it dries very quickly to a matte finish, and it writes equally well on both light and dark papers. When used alone or mixed with any other color, gouache absolutely pops off the page. It also doesn’t get absorbed into the paper, so when dry, it has a dramatic, raised quality.
Straight out of the tube, gouache is a thick paste and requires mixing with water to reach the right consistency. What differentiates gouache from watercolor is that its pigment is more highly concentrated, the pigment molecules are larger, and it usually contains white pigment (like chalk), which makes it opaque. Unlike watercolor and ink, which get lighter when more water is added to them, gouache colors can only be lightened by mixing them with a lighter color of gouache.
Brands of gouache vary greatly in quality. Generally, the higher the grade of gouache, the more finely ground the pigment is, which means it will flow more smoothly through the fine tines of your nib. For beginners, low- to mid-priced gouache is a perfectly acceptable choice.
Mix gouache using a short-bristled paintbrush and adding small amounts of water a little bit at a time until it reaches a consistency somewhere between whole milk and a beaten egg yolk. I use an eyedropper to add the water so that I don’t risk adding too much. If you’re blending multiple colors together, mix the colors with each other first until you get the desired color, then add the water. Keep adding gouache as needed. It is important to know that gouache dries to a darker shade than it looks when wet, so make small swatches and let them dry as you mix to be sure you get the desired color.
I always keep permanent white, jet black, primary red, primary yellow, and primary blue gouaches on hand. If you own these five colors, you will be able to mix just about any color under the sun. You can lighten or darken colors by adding white or black, respectively. Make browns by combining the three primaries: red, yellow, and blue. Warm up colors by adding a touch of yellow and cool them with a touch of blue. Gray is, of course, white and black, but that mixture alone can look cold, so add a hint of yellow for a softer gray. Metallic and neon gouaches don’t mix very well so it’s best to buy those colors premixed. Watercolor and gouache can also be mixed together, which is convenient for turning a translucent watercolor opaque.
Since gouache dries quickly, mix it in resealable containers. This is especially important if you mix a large batch of color for a project that you’ll be working on over the course of days or weeks. Even in resealable containers, though, mixed gouache will start to thicken over time. If this happens, simply add more water until it’s the right consistency again.
Gouache is absolutely fantastic for doing light-colored calligraphy on dark paper. That said, I recommend first working with dark gouache on light paper. Until you have more experience, light writing on dark paper poses its own challenges, covered in an upcoming section, “Light Writing on Dark Paper” (here).
Gouache is not only thick before adding water, but as it dries it goes through a “muddy” phase before solidifying. This means that you can’t draw your nib over gouache calligraphy to thicken or refine a stroke unless you do it quickly, while the letters are still very wet, or unless you wait until it’s completely dry.
Fill your calligraphy nib with gouache either by dipping it directly into a pot or applying it to the nib using a paintbrush. The first time you try to make a stroke, it probably won’t work. You have to start the flow of color through the nib by dipping the very tip of the pen in water. If you still can’t get a stroke, or if the flow stops during the upstrokes, then your gouache is probably too thick.
A nib full of gouache will not last as long as a nib full of ink, so you will have to refill your pen more often, sometimes even mid-word. (Try not to refill in the middle of a stroke, but, rather, at the intersection of up strokes and downstrokes.) As you work and gouache begins to dry on your nib, you will encounter flow issues again. Wash your nib thoroughly in clean water using a soft paintbrush. (I normally have to do this every fifteen to twenty minutes.) You will find that gouache calligraphy is more time consuming and a little more labor intensive than ink, but the results, many of which cannot be achieved any other way, are worth the effort.
Ink and watercolor washes are versatile, abstract designs that can be used as backgrounds with calligraphy written directly on top, or as uncalligraphed complements to a calligraphy project, like envelope liners that incorporate the colors of the calligraphy on the card that goes inside.