I paint with acrylic paints as water media. My last painting on cold-pressed paper came loose from the tape as I was working on it, and I'd like to know how I can get it flat again. In addition to using acrylic paint, I also used some poured artist's ink.

This is why I use staples instead of gummed tape. The tape can let you down if it gets too wet.

The acrylic by itself would be fine to dampen and restretch. I don't think the ink would fare very well, though.

You can lightly (!) dampen the BACK only, with a sponge, and then put it inside a drawing pad or sandwich between cardboards of the right size, weighting it down on the top with as many books and heavy objects as you can pile onto it.

Everyone knows that you can't put heavy weights on the surface of acrylic paintings... it sticks and pulls off the paint!

If you don't want it to get damaged, you will have to mount it on mat board. You do this by using rubber cement. Spray cement will work well. You spray the back of your art work, and the board you will mount on with contact cement, then CAREFULLY place the center of your painting on the mat board. Then using a rubber roller roll from the center of your painting out towards the corners, pushing out the wrinkles as you go.

Unfortunately rippling is a natural effect of watercolor painting on paper. The best treatment (from a conservation stand point) is to mat it using rag matboards. Make sure you hinge it from the top only, this will allow the paper to hang naturally, with out any pulls. If the water color has any value/means something personal to you - please don't use any of the above treatments. Look at it as part of the paintings personality. Hope this helps.