STELLUX™ Austrian Crystal FLAT BACK HOTFIX JET HEMATITEFlat Backs Hotfix can be easily ironed on to textile materials such as wool, cotton, linen, viscose, lycra, alcantara, silk, synthetics and denim, to name just a few. The flat back of the crystal has a layer of hot melt adhesive that is activated by using heat and then bonds with the carrier material. They are wash resistant and come in a multitude of colours, sizes and cuts. They can also be used as no hotfix, using glue on application method.