Application Directions: Heat press the image on the garment with its polyester carrier protected by a Teflon sheet at 300-360 degrees F for about 15 – 20 seconds with medium pressure. Peel carrier off cold.
Wash Instructions: Temperatures up to 180 degrees F inside out.
I have home ironed on the letters with a towel instead of the Teflon sheet and have also used nothing between the iron the carrier(letters) and it worked also.
Demonstration videos: https://www.youtube.com/watch?v=P0m9AuyKSm4 and https://youtu.be/IZqIRDeWAVs