Irone on Rhinestone Letter DIY Patch, immediate ship from USA If you need exact position for these letters, you can use E6000 or any fabric glue to put the glue on the back of the letters and then put it on your backpack or cloth or anything you want. leave it out for 5-6 hours, and it will be perfectly glued on. you can also iron on by ironing it on backwards. Meaning that you flip the letter backsword and then put the cloth/fabric on it. Afterwards, use heat press to press both fabric and letter for 10-20 second. Done, but for this method, you can also use the fabric pan to draw the outline of the position of the letter first, and then if you can see the tracing mark, it will be easy for you to position the letters based on the trace backswords.