My painting, "Daddy's Funny" is starting to ripple. It's the second time using polyester canvas and it looks like maybe I didn't put enough staples in the back. They are spaced about every 2 inches. It's only rippling on the longer edges of the painting and not the shorter edge. It's 18x24. So, after this dries, what do you think I should do? I've never had this happen...although "Pensive" which is on linen is starting to do the same. My paintings on cotton canvas has not done anything unusual. My only other painting that is on poly canvas is "Wedding Flowers" and that is not showing any issues, but it is quite a bit smaller.
Do you think it could be glued down to masonite or hard board? Re-stretching sounds like I could easily ruin the painting.