What is Dye Sublimation?
Most polyester fabrics, such as many of the popular “Performance Garments”, are dyed using a sublimation process. The dye sublimation process uses high heat to permanently fuse the colorant into a polyester fabric.
Heat serves two critical functions in this dying process. First, the heat causes the pores of the polyester fabric to open up, so the material can accept the dye. And second, the heat converts the solid ink dye on a transfer sheet into a gas.
Under pressure of the heat press, the gaseous dye is forced into the open pores of the polyester. As the temperature drops, the pores close up capturing the dye inside of the bonds to the substrate.
The sublimated color is very durable because the dye becomes an integral part of the fabric, rather than a colorant on the outside of the fibers of the fabric, which can bleed and fade. Sublimated fabrics can be washed again and again, without losing the vibrancy of its color.
Dye Migration Can Discolor Heat Transfer Appliques
There’s one slight catch, though. When you heat press an applique onto a sublimated garment, the high heat can release the dye in the fabric. These dyes can then migrate and discolor a heat transfer vinyl applique.
Discoloration resulting from dye migration does not occur immediately. Instead it is a gradual process, which may take as long as 72 hours to occur. For example, a white applique heat pressed onto a black sublimated garment is likely to turn gray over time.
