Heat transfer vinyl (HTV) is a speciality polyurethane with a heat-activated adhesive (typically polyester-based) that can be used on certain fabrics and materials to apply designs to promotional products, textiles and apparel, such as T-shirts.
It comes laminated together with a clear polyester carrier in a roll or sheet form, with an adhesive tacky backing, so it can be cut, weeded, and placed on a substrate for application via a heat press.
The tacky adhesive between the carrier and the vinyl holds together complex designs, although the labour naturally increases the more weeding that is required.
Heat transfer vinyl is made in single colors and also has special options such as patterned, glitter, flocked, holographic, glow-in-the-dark, reflective and 3D puff.
Heat transfer vinyl also benefits from a high degree of stretch and rebound, achieved by a memory effect, making it suitable for use on apparel and other flexible items including the garments typically used, such as sports jerseys.
Heat transfer vinyl can be used to create special effects with its glitter, flocked, holographic, glow-in-the-dark, and 3D puff options.
Despite being commonly referred to as vinyl, the material does not contain PVC, meaning it is generally considered non-toxic, and sometimes (for instance in Europe) carries internationally recognised ecological certifications such as from Oeko-Tex (although laboratories including SGS S.A. are also used).
Thus, the use of heat transfer vinyl to decorate apparel is often cited as an ecologically friendly alternative to plastisol screen-printing inks, that is despite the consumable nature of the plastics involved.