The binder is what makes pigment stick to the paper. Watercolor binder is made from water-soluble tree gums. This particular listing uses gum Arabic, which is harvested from one of two types of acacia trees that grow in Africa.
It can also be made using the gums from peach, cherry, and plum trees. I haven’t done any studies on how these gums affect the stability or permanence of pigments, however, the ability to use a locally foraged ingredient rather than one imported from far away, is a temptation. Eventually, I’ll do some comparison studies and research this option more.
When I make my own watercolor binder, I usually make several bottles and sell the extra. One bottle lasts me for several months if kept in the refrigerator after opening.
Watercolor Binder Quality Control
I test each batch to make sure it performs to my own expectations. Things I’m concerned about include whether it dries without being tacky, wets easily enough (different pigments have different personalities, and some might need more time to wet… or ‘wake up’), minimizes cracking, etc. But the most important things I note: are the colors vibrant as expected, and will it smudge after it dries (it definitely should not). If those two criteria are met, I am happy.
How to Use
When making paints using dry pigment powders, you’ll need to get a feel for how much binder each different type of pigment needs. If your paints crack when drying, try adding a little more binder during mulling. Pour thin layers at a time into the pans and let each layer dry thoroughly. To make sheer paints with a little more gloss, I make a thinner paint. Sometimes I also pour up a pan of just the media so that I have a pan on hand if I want to add a little gloss to highlights in my paintings.
Here’s my general recipe if you’d like to make your own. If you make enough volume and use heat sealing lids, you can preserve them in a water bath just as you would can jelly or preserves. I sell the pre-measured 5Tbs packs of powdered gum Arabic, as well.
Using powdered food-grade gum Arabic:
Makes one cup:
- 5T powdered gum Arabic
- 1/8 c honey
- 2 drops clove essential oil (not fragrance oil)
- 1 cup water
Boil the water. Put all of the other ingredients in a bowl. Once the water is boiling, add a little to the bowl so that you can stir the ingredients with a fork into a paste. Try not to let it make lumps. Slowly add the rest of the water while stirring. Bottle it while hot and refrigerate once opened. My bottle of media lasts months in the refrigerator.
Using whole gum Arabic tears/resin
- Start with a quart jar
- Add 1″ layer of raw gum Arabic resin
- Fill to curve of neck with boiled water
- Agitate to dissolve the resin once the water cools enough to handle
In another container, add 1/10 volume with honey, fill the rest with your gum Arabic solution.
Add 1-2 drops of clove or cinnamon essential oil.