Previously our pre-printed patterns required Siser TTD mask for application. We have now improved our process to eliminate the need to purchase a separate sheet of mask. You can now cut, weed, and apply our pre-printed sheets just as you would standard Siser Easyweed Heat Transfer Vinyl (HTV). Simply cut your design in mirror (reverse) on the white side of the sheet (side that is not printed) , weed, and press just as your would a sheet of solid color EasyWeed.