When you get going at this - you might want to consider going with baltic birch plywood. If you are getting your ply at the hardware store - you will have voids and spots that won't cut right. When you buy plywood from a supplier of scrollsaw wood, you will find more plys and no voids. For practice purposes, anything you can get your hands on will do, but you will see and feel a noticable difference when you move up to better wood.