This post is from the PRU’s, but when you accepted shipment you should have got a similar page that showed you stuff in this format: heading, done, to do. If you got your machine recently it would have said printing area of 11"x19.5" instead of the 10"x18.5" that is quoted here. (It’s actually a few thousandths smaller than quoted, say 10.97" and 19.45" which folks have discovered by experimentation, I suspect the limit is actually set in mm or stepper steps internally.)