Today let's look at various painting mediums.
All artists colors contain one common thing and that is the pigment in it. It's the pigment that we see as color.
They are derived from minerals, organic sources or chemicals.
Medium is the thing which carries these pigments and keep them fixed in one place on the painting. Those are the things we'll be talking about today.
Oil colors use oils like linseed oil, walnut oil or safflower oil as the medium. When exposed to air, these oils oxidise and form a film that holds the pigment in one place. This is a slow process and hence oil colors take long time to dry.
Oil colors themselves are not toxic but the mineral spirits used with oil colors are toxic. But nowadays you also get water mixable oil colors that you can thin and also clean with water.
Watercolours use water as the medium. Water evaporates and the pigment remains on the paper. Some gum arabic is also added to the colors so that it provides binding to the pigment.
Acrylic is a recent medium that was invented around 1950s. It's a plastic polymer that forms a film when the water in it evaporates. Hence acrylic colors dry fast and are not re-workable.
These are very much like watercolours but are more opaque. They can be rewetted and worked on.
Casein colors also use water as the medium but also have a milk protein in it as a binder. This makes the paint film permanent once it dries.
Pastels uses much higher percentage of pigment. Depending on the quantity of binder in it, it can be a soft pastel or a hard pastel.
Every medium has its advantages and disadvantages. It's upto us artists which mediums we choose to work with.
Let me know your most favourite medium in the comments below!