|
I second what Chris has said. You use a medium to alter the paint to a consistency and workability that works for you. For some, that means they use medium all the time. For others, none at all. It all depends on if you can get the paint to do what you want it to do without it, or with it.
Now, there are certain times that you want other characteristics to paint other than brushability - like you want it to dry overnight, or you want to glaze with it, or you want more of a jewel-like quality to the paint, or you have a painting that has been sitting in a corner for 3 years and you pick it up again. Mediums often contain driers which can allow you to paint again the next day, or resins which can help with adhesion in works with underlayers that are dry and shiny.
Certainly the fat over lean guidelines apply if you are using paint with no driers added.
|