Most of these pendants call for either resin mix or clear cabochon that fits the pendant blank exactly. You can make them with only clear and white nail polish. Cut the printout to the size of the blank, brush white nail polish to the back side of the print out and let it dry. Brush a thick layer of white nail polish to the metal blank, make sure you cover the entire empty space, then immediately put the printout over the new nail polish, make sure there's no air bubble. The two should bind together. After it dried completely, brush with many layers of clear nail polish.