"He who marches out of step hears another drum." ~ Ken Kesey
I believe Fed Ex envelopes made of Tyvek are printed with UV obviously that will not work for us.[/quoteDo you have a forced air dryer? I bet a fast evaporating solvent ink would dry before they hit the other end. Run little to no heat and as fast as that stuff dries it might work. Just a thought. I dont know if it works on Tyvek but it did on some electrical panels we did.