I've been using old jigsaw puzzles in my artwork for several years. I like to use various shapes and sizes of puzzles to give the finished piece a variety of textures. My latest technique is to make them into quilt blocks.
First I put the puzzle together, and paint the puzzle (picture side) with two coats of Gesso. Then I cover the back side with a coat of gel medium. When everything is dry I colorwash the gesso side with colors that will work into finished quilt block.When the colorwash is dry, I cover the colorwashed side with a clear glaze. Then I use an Xacto knife to cut the puzzles into quilt shapes. ( I might have to use 4 or 5 puzzles to get enough pieces to make the quilt block.) Then I "piece" them together to make a quilt block.
I've loved puzzles all my life and I believe that is big reason why became attracted to quilting, Quilting is like creating a giant fabric puzzle.