Oval Stamping Blanks - 30mm x 22mm £0.40 These are oval stamping blanks that measure 30mm by 22mm in size. They are cut by hand from 1.2mm thick/16 gauge aluminium so are nice and thick to stamp on and get a good impression. As they are cut by hand the sizes and shapes do vary slightly. Aluminium is a great alternative to sterling silver as it does not tarnish, is light weight and you can polish it up to give a lovely shine. Try stacking these oval blanks both ways in necklaces, they look great.