For maximum adhesion of your hot fix crystals, the “water drop” test can be used on potential fabrics or materials. The optimum bond can only be achieved if the carrier material can absorb the glue. If the fabric has a waterproofing finish, it will not absorb drops of water or glue. The water must penetrate the material. With fabrics that contain a large quantity of softening agents, adhesion can be improved by washing the original materials before the application process. Very fine fabrics such as organza, as well as smooth leather, smooth leather imitations, tightly woven polyamides and fabrics with a silicone or wax finish may not be suitable for hot fix applications because they are unable to absorb the glue.