Fuse a stack of plastic shopping bags into a durable, water-resistant carryall, great for toting sleepover gear, wet bathing suits, or sandy beach treasures.
Cut the handles and bottoms from 8 shopping bags. Arrange the bags into two equal stacks. Make sure any printing on the top and bottom bags faces inward.
Sandwich one of the stacks between two pieces of parchment paper, making sure the plastic is entirely covered. Beginning with the iron on a low setting, such as synthetics, move it steadily over the stack until the bags shrink and fuse together. If the bags do not fuse after 2 or 3 minutes, increase the iron's temperature. You may need to experiment to get the heat just right. Avoid touching the plastic directly with the hot iron. Set the fused sheet aside and repeat with the other stack.
To create one long sheet of plastic, lay the two sheets end-to-end, overlapping by one inch. Then iron the overlap between layers of parchment paper to fuse the sheets together.
Have your child choose colored plastic bag strips to decorate the outside of the sheet. Iron these plastic pieces to the sheet between parchment paper, as in step 2.
Lay the sheet decorated-side down. Fold it so that the short ends match up, and tape the sides of the bag together. Trim the top of the bag to even the edges. For each handle, lay a 9-inch-long piece of tape in the center of an 18-inch-long piece, sticky sides together, then tape the handles to the inside of the bag.