The only surefire way to preserve your children’s art is to frame it and mount it using acid-free paper and matting. This protects the piece from bugs and handling. The other big issue to consider is where to hang the art once you have it framed. Remember that light is the biggest danger for art on paper, so always hang pieces in locations that don’t receive direct sunlight. Also consider framing them with UV-filtering glass.
Don’t Forget: a piece of three-dimensional art gets wet, you have only a few hours before the beans sprout, the glue loosens, and the pasta dissolves. Dry it as soon as possible with a blow-dryer or a fan set on low. Otherwise you might as well plant the beans and eat the pasta.