Living in Hawaii, I'm always nervous when buying anything online because of the shipping cost and delivery time. Of all the Mainland vendors I've worked with in the past, LCI is by far the best. Their delivery time, wide selection and prompt shipping is great. Their customer service reps are outstanding! Wish I had found you sooner!
People have been using The Perfect Printing Pouch for many years without any harmful effects. But do understand, neither LCI Paper nor ScraPerfect will be held responsible for damages resulting from printing on materials not specifically recommended for your printer.
Here's what Epson says about the pouch in their Epson Print Lab series booklet: Scrapbook Projects
Hot tipFor any vellums you encounter which resist being printed, we recommend you try The Perfect Printing Pouch. It is a pouch filled with a formula of acid-free, talc-free, non-toxic powders. Prior to printing, lightly tap the pouch over the area where you wish to print to release the powder onto the vellum surface. The powder makes the ink adhere to the paper and speeds drying. It works well on patterned, coated, and colored vellum as well as on many glossy, textured, handmade and coated papers. We recommend that after using the pouch, run a plain sheet of paper through your printer to remove any excess powder from the inside of your printer.