The instructions for heat bonding are as follows: The temperature required is dependent on several variables including dwell time and applied pressure. Increasing dwell time and heat results in predictable color shifts in the fiber. Approximate bonding temperature is around 225 degrees Fahrenheit. Since temperature gauges on irons vary widely even within most brand models, it is best to test a small amount to determine your correct bonding temperature. Simply place a small amount of fiber between two sheets of tissue paper. Heat iron to silk temperature setting. Gently, with little pressure, move the iron back and forth, checking frequently on the bonding progress. Be careful not to "fry" the Angelina fiber with too much heat or pressure and a too long dwell time. Generally, Angelina heat bondable fiber will only adhere to itself and not to other fibers, tissue paper or fabrics.