Or in lieu of a jacket hold down you can pull it tight on the pallet and use binder clips to hold in place. Keep in mind if you have a bunch to do tape the bottom of the screen over the areas the clips touch with painters, duct or block out so they don't rip the screen. Its a pain clipping each one but it beats buying a jacket hold down if your only doing a couple a year. I only do maybe 75-100 jackets a year, maybe 10 at a time so it works fine for me. We did a dozen hooded zipper sweatshirts with a loose lining 4 color, left chest and full back a few weeks back and nylon with a lining last Monday this way. Usually two clips on each side of the pallet. Don't get me wrong a jacket pallet is the way to go but there are other ways.
When I am doing nylon I lay it on the pallet, flash for a second or two low heat which flattens the wrinkles out then clamp, print and off.