Most crackle mediums act by applying a layer of the crackle medium on top of an acrylic painted surface, allowing it to dry, and then painting a 2nd coat of acrylic paint over that layer which crackles as it dries. You can make your own crackle medium by applying Elmer's glue on to the 1st layer of paint, allowing it to become tacky, and then applying 2nd coat of acrylic paint.... when it dries, it crackles. Does anyone know how to create a crackled appearance on a photo or picture? Can glue be used? Whatever the applied mediums are, they must be transparent to allow the image to show through, and yet be cracked.