Binders are the body of the paint it brings and keeps the pigment in place. The correct binder is very important. Not all binders work on every surface and not all can resist the elements. Common natural binders are casein, lime, chalk, clay, glue and oil. The easiest to buy is probably wall paper glue this is made out of modified starch and methyl cellulose. The easiest to make is almost the same but made out of wheat grain. If you boil the flour you get a paste that can be used as an adhesive.
The Binder
- Slaked chalk also called calcium hydroxide is often used for interior walls because it's very white. It's very easy to apply and you can also easily clean the brushes. The result is a durable and stain proof wall.
- Lime based paint is also used for interior walls but it's strong enough to use it for exterior walls. It's cheap and natural.
- Casein is the binder that is used in milk paints. Not the strongest paint but it works for interior walls. The binder works the best if applied thinly.
- Wall paper glue is a great binder made of plant material. It's probably the easiest to make you only need to add pigment.
- Oil is expensive so it's mostly used for woodwork and small art. Examples are tung oil and linseed oil. The modern linseed oil isn't very healthy anymore so pay attention to the packaging.
- Eggs are surprisingly also used to make paint. Many famous painters from the past used tempera paint what is made from eggs. The paint stays good as long as it stays dry. It can be used for kids paintings or normal painting. To use it for interior walls you need allot of eggs so that's maybe not the best choice. If you mix water with pigment and a egg yolk you have made Tempera. It's that easy!