Thermal transfer printing can be carried out using flex or flock foils. The flex film is thinner and allows you to get a smooth, rigid print. Flock, on the other hand, is a thicker foil with a characteristic velvety, "nappy" structure. Properly prepared foil, high pressure and high temperature are necessary for the quality of flex/flock printing.
This type of printing is relatively cheap (start-up costs are small), quick to prepare and can be successfully used for the production of single copies. It works well for simple inscriptions or symbols on textiles. It can also be easily used where overprinting with other methods is difficult or impossible.
Both flex and flock ensure perfect colour coverage and are considered to be fairly durable. However, they are rarely used to transfer more complex graphics onto garments - especially those with tonal transitions between colours or with small elements. The number of colours that can be used for flex or flox prints is also limited.