I print on them all the time. Tips for polyester dryfits:
- Make sure you are using a Low Bleed Polyester Ink. This will help to avoid dye migration.
- Some Dryfits are really stretchy and You want to add a stretch additive to your ink. I didn't add any for the AS 790's because they don't have a lot of stretch to them.
- Make sure to raise your flash/ conveyor heat source. You want the polyester to gradually come up to temperature. A lot of shops set their flashes and/or conveyors to cure as quickly as possible which you can get away with when curing most Cotton shirts. This is a NO NO for polyester. You want to the polyester to hit your curing temp very slowly. This will keep the dyes in the Polyester from migrating into the ink. The last thing you want is a Red polyester dryfit to turn your ink a Pink Color.