can i add another question to whoever replies? i've been wondering the same thing, plus some of my pics have newspaper and watercolors. will the seals smudge or blur them?
I seal my acrylic paintings with a brush on sealant rather than spray ones. I think it keeps chemicals to a low just cause they are not flying around in the air. Once they dry they are pretty safe. I found some at Micheal's craft store that works great.