I use special sublimation ink that turns into gas under high temperatures and PERMANENTLY dyes high polyester or polyester blend fabric. It will be transfered to the shirt fibers and will last the entire life of the garment. No special washing instructions, no cracking, and no feel to the design on shirt. High polyester shirts also have a wonderful butter soft feel! Your high resolution image/ design will transfer best on white shirts. However I can sublimate on LIGHT COLORED shirts. All dark colored shirts will have to use normal transfer process.