Textile screen printers have used plastisol puff inks for years. These inks contain a special additive that causes the ink to expand after it is exposed to heat. RTape/SEF FlexCut Sweet Puff films work in much the same way.
Before the film is processed, FlexCut Sweet Puff looks like and cuts just like any other thin polyurethane heat transfer film. But once heat is applied, this unique puff film magically inflates creating a three-dimensional applique.
Using a drag knife or tangential knife plotter, graphics are cut in reverse (wrong reading). In designing appliques graphic artists should keep in mind than the film will expand. That means, that you should allow some room for the graphics to grow. Spaces less than 1/8” (3.2mm) will likely disappear, after the film expands.
Also keep in mind that as the film expands, its color will change. FlexCut Sweet Puff is available in six popular colors: White, Lemon Yellow, Electric Red, Reflex Blue, Green and Black.
After the graphics are cut and weed, the next step is heat pressing. FlexCut Sweet Puff is designed for application to cotton, polyester and blended fabrics. It is not suitable for application to nylon or coated fabrics.
After preheating the fabric in the heat press for three to four seconds, transfer the puff film to the garment and press it at 330⁰F (165⁰C) for 15 seconds at low pressure.
Pressure is a key factor determining how high the applique will expand. At a higher setting, the pressure of the press restricts the expansion of the film. As the pressure setting is lowered, the film will expand more.
Pressure isn’t the only factor determining the expansion of the film. If the polyester carrier is removed hot, the film will expand to a greater degree.
In caring for the graphics, always wash and dry garments at low temperature settings.