Painting over old painting help!!!!?

Question:

Painting over old painting help!!!!?

If I have this painting and I'm not sur eif it's acrylic or oil can I paint over it with gesso and then paint on the gesso with oul or acrylic? All I know is that you can't paint over oil with acrylic, but where does gesso come into that? So besically can you paint over oil with gesso and can you paint over acrylic with gesso (and cover up a previous painting so you can paint a new one)? Thanks!

Best Answer - Chosen by Asker: Is there a transparent primer with which I can paint over acrylic paintings so I can paint oils over the acrylic?
We commonly recommend the Matte Medium or the Fluid Matte Medium brushed evenly as a transparent gesso. This adds tooth to glossier acrylics and can also be used as the initial primer for times when the support needs to show.

Much more here:

http://www.goldenpaints.com/technicaldat...