Everybody's taste in art is different. One person's masterpiece might be another's garbage, so unless a guest knows the bride and groom's tastes well, art shouldn't be purchased as a wedding present.
Imposing funky art on someone else is a crime; offenders include a paint-by-number disguised as an expensive piece of art and an acrostic name poem written on a sheet of notebook paper. One bride received a fertility statue from her aunt, who explained it should go next to the bed for help conceiving a child.
Although the gift-giver's intentions might be good, no one wants the lopsided, lumpy bowl that was crafted in an entry-level pottery class. It's likely to last a very short time on the couple's bookshelf before making its way to Craigslist's "free stuff" listings.
But what do you say if Aunt Edna paints your portrait, and it's less than flattering? Accept the gift graciously, but resist the urge to haul it straight to the trash can. Hang it in a special place in your home -- but only when she is visits.