GUM ARABIC:
What is it? It is a gum from an acacia tree in Africa. It is non-toxic. We buy it in a sticky liquid form, amber colored, but it can also be found in crystal form.
What does it do? It is the binding agent in paint. It is what glues the pigment to the surface. It can: extend the drying time of paint; give glow and transparency to paint; act as a temporary soft masking agent.
Note: QoR paints use a synthetic binder that is clear to replace the gum arabic.
How can I use it?
1. To make your own paints. Mix it with dry pigment, ox gall, and glycerine.
2. To make gouache behave more like transparent watercolor: Add a drop or two to your gouache
on the palette. It will reconstitute faster (normally you have to rewet gouache for 15minutes to be usable) and be more transparent, with less matt finish.
3. As a mask: apply straight from the bottle onto paper with a brush. Dry completely. Wash over
with watercolor. DO NOT MAKE MANY PASSES WITH THE BRUSH AND PAINT, as the gum
arabic is water soluble. When paint is dry, gently remove from masked area with water and brush.
Turner did this for scenes with moonlight.
Above is the experiment I set up for myself to see how well gum arabic can mask. I used removable
masking, permanent mask, gum arabic, and lifting preparation.
You can see from the top row, third circle from left, the gum arabic left a nice white shape with gentle edges that do not need to be softened.
4. Add glow and transparency to your wc paints: You can add a few drops to a cup of clean water
to the water you will use for wetting your paints. The more gum arabic added to the water the more glow to the paints.
5. En plain aire, it can extend the drying time of your washes, and give you a little more time to
work with blending the paint and prevent blossoms.
What are the cautions?
*Using too strong a solution of gum arabic can result in a brittle surface and make the paint flake.
*When using as a mask, if you brush over it too much, it will blend in with your wash instead of
masking it.
GLYCERINE:
What is it? It is a colorless, odorless, viscous liquid that is widely used in watercolors. Glycerin is soluble in water and is hygroscopic. The glycerin backbone is central to all lipids known as triglycerides. Glycerin is sweet-tasting and is non-toxic.
Glycerin is an humectant (attracts moisture) and plasticizer ingredient in commercial watercolors today. It is used widely in candies and frostings, lotions and make-up.
What does it do?
Glycerine is used in almost all watercolors today. It extends drying timeand helps the gum arabic redissolve in water. Its main purpose is to be a plasticizer and makes gum arabic more flexible and prevents it from turning brittle.
Winsor and Newton became top manufacturers of watercolors when in 1832 they began adding glycerine to their pan paints to help them reconstitute better.
How can I use it? 1. To reconstitute dried up paints or student grade paints. Put a drop or two on top of dried paints and let it sit covered.
2. You can add it to your tube paints, especially student grade, to prevent them from cracking in the wells of the palette.
3. You can use it as an ingredient in creating your own paint from pigments or add to gouache.
What are the cautions? None
HONEY:
What is it? Ummm.....I think you know that one.
What does it do? Honey is a humectant, and it doesn't seem to degrade over the years. Jars of honey over 100 years old have been found still good. In watercolor paint, such as M. Graham, it is used to keep the paint moist and buttery in consistency when you spread it.
How can I use it?
Honey, like glycerine, can be used in small drops to reconstitute dried, cracking paints or mixed in with tube paints to improve the consistency and spread.
Cautions?
Some of the sites I've read say that paints made with honey are more staining than their counterparts that are made without it. (same basic pigment, but different binders.)
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