I am new to the heat press world. Starting my first job on 100% black poly (Hanes Cool-Fit t-shirt). I have purchased polytrans tranfers through the recommendation from the company. When I use the recommended heat, 340 for 10 seconds, I get a shinny press area. They told me that it will disappear in a couple of hours but I have waited and washed the garment and it is still there. I have been able to make it work at a much lower temp, 275 for 15 seconds, and the transfer seems fine. Are there going to be problems with the transfer after time? Is there a different method or setting that I should use? I really need this to work because I have purchased alot of t-shirts and tranfers and have a tight timeline for the customer.