As an oil colorist it is important to work on oil primed surfaces and not universal primed surfaces. The reason is that universal primed surfaces are semi-absorbent. Gesso is absorbent even if it is plate smooth. Granted it is not highly absorbent but the fact remains that some oil will get into the primer and flatten the image. You can get around this by using an underpainting oil ground on top of the surface of a universal ground canvas but this is very time consuming and expensive. Unlike universal ground our oil priming chemically bonds with the oil paint and is non-absorbent allowing the paint to sit up on the surface with the correct refraction quality of the oil binder. If you use any high quality oil color we urge you to use an oil primed surface and now we make it affordable!