Make sure your garment is
DRY. Prepress 10 seconds, lift, let steam escape, press another 10-plus seconds.
Yes, check time/pressure/temp. Cut up your transfer and test on similar goof shirts.
I'm going
25 seconds on plastisol,
medium heavy pressure, 375 F. I warm/hot peel my opaque white after rolling with Speedball brayer (because image is delicate/small). It was reading through archives here that someone mentioned using a rolling pin. Well, I had the brayer and actually like the ergonomics better.
For black plastisol, I must peel warm/cold or the text ends up "smeary". I also run the Speedball brayer a few times only because I've got some delicate images (thin lines).
AND, try flipping shirt onto a teflon sheet or Reynold's Baking Parchment Paper (one of my readily available inexpensive heat pressing tools) and repress for half the time on the
backside.
The Reynold's paper is about $2.99 and you can re-use it until brittle or you think it's been soiled with ink.
I was having problem with t-shirt pilling on some 2XLs. It was NOT LINT, nor time/pressure/temp. A seasoned pro advised me to flip the shirt...wow, it worked great on my TransJetII/Magic Jet II transfer. Made the image look so much better that I started doing this with big full page transfers.
Susan