Interesting. I'll definitely try the 285 @ 20.Sublimation and vinyl are 2 different things. You will not have any issues with sublimation you might need to play a bit with heat and time depending on the shirts you get, when going with vinyl, keep in mind that any polyester does not like to be heated above 300 degrees. We use just standard Siser Easyweed on polyester and after working with the Siser techs we nailed it that we can press the easyweed on poly at 285 for 20 seconds with no issue and it doesn't come off. No need for special vinyls. We use the Easyweed and this technique on all the sports uniforms we do for numbers and names and have no issues at all.