I decided to make this blog because so many of my collectors have asked me about this...so I felt that it was only right to talk about it. So the reason why we prime a canvas is because we need whats called a 'ground' in order for us to apply the oil paint. This creates grit or otherwise known as 'tooth' which is were the oil paint hold on. You see, oil paint binds mechanically (it has to latch on) as opposed to it's cousin; acrylic paint which binds chemically. Another reason besides the obvious why you should prime your canvas is because - the canvases you buy from the store (specially rolled canvas) may not be primed or may have low-grade canvas; making painting a real pain in the behind.