I recommend that you only use spray adhesive on soft goods like mouse pads, can koozies, and garments. There are some hard surface items where you must use spray adhesive, like awards plaques, as tape can damage the edges. For those items and soft goods, it is very important that you spray the adhesive correctly. Spray the printed side of the transfer paper, not the substrate, with a very light and fine mist. To do this, you should spray the transfer paper from about two feet away in a firm, quick spray over the transfer paper. If you get any splotches or excessively wet areas, you will have trouble with the ink transferring correctly in that area, so pay close attention to the amount of tack you are spraying.
—2 Regular Guys