OK, walk into your nearest art supply store and buy 1 tube of the cheapest oil paint you can find. Pick the hue COBALT BLUE. When you squeeze the paint from the tube you will find gobs of gooey stuff amongst the pigment. That my friend is a lot of (low quality) binder. Low-end paints are packed with the stuff because the raw pigment (especially a hue like COBALT) is the most expensive ingredient.
So... WHY GRIND YOUR OWN OIL PAINTS? Because you can control the quantity and quality of the binder and the paint pigment itself. You will be able to achieve richer, deeper, more saturated... effects. GRIND YOUR OWN OIL PAINTS! You're worth it.
I'll cover: how to grind oil paints and choosing binders in my next blogs.