I’m writing this for one but obviously multiply it by however many placemats you want! And a speed tip from a girl who sews a whole lot of the same thing over and over (ahem for my shop), cut all your pieces out at once and do the same step for all of them at the same time (as opposed to making one placemat completely and then starting another). Alternatively for motivation you might want to do one full one first or just a few so that you (or your sewing minions can feel successful and excited to keep going).