DSF

we have been playing with cutting text in white vinyl, pressing onto a T, then subbing an image on top.
160c for 1min gives a nice but weak result, if we go too hot, or too long, the image gets slightly stronger, but the adhesive degrades and the vinyl lifts or comes off. (using Poly-Flex / TMT premium flex)
Is there a sweet spot or any top tips?

Poly flex, I believe , is polyurathane , not polyester. Or it might be a brand name for Polytape, the vinyl making company. This will probably be the reason it comes out light.
Have you tried doing it with subli flock? Cut, weed , print then press onto the shirt. Its fiddely but it works.

If I sub flock will it not crush the pile out of it? - My regular supplier (TMT) doesn't do a subliflock, - so nothing to play with.
Reason I played with Poly-Flex is a thread i read on tshirt forums dot com

The Subli flock I use has vertually no pile so it feels like a thick Flex. Its a bit of a pig to cut and then print because the carrier ( a waxy paper) is not sticky.
If you have a cutter with an optical laser reader then you could print first and then cut.