Heat transfer vinyl, or HTV for short, is a specialty vinyl polymer that can be used on certain fabrics and materials to create designs and promotional products. It comes in a roll or sheet form with an adhesive backing so it can be cut, weeded, and placed on a substrate for heat application. Heat transfer vinyl is made in single colors and is best used for simple designs with minimal colors since each individual color or pattern used in the design must be cut, weeded, and heat pressed. Certain heat transfer vinyl can be layered to form multi-colored designs. The more layers involved, the harder it is to match up each to achieve the end result. Heat transfer vinyl cannot be used for full-color pictures or anything with gradients. There are other applications for those options.Because of the nature of the way the vinyl is applied, it must be used on products that can take the heat and pressure required to make the transfer adhere properly. For fabrics and clothing, typically this is temperatures in the range of 250-300 deg Fahrenheit / 120-150 degrees Celcius. The product (also known as a substrate) will also need to hold up under the clamping action and pressure of the heat press.