You can personalize slowpitch softball jerseys by creating a design on a transfer paper. This paper is then placed on a sublimation printing press and heated to about 400 degrees Celsius. The high pressure creates a chemical reaction that sublimates the ink directly into the polyester fabric. The entire process takes approximately thirty to forty-five seconds. After printing, the fabr... https://www.apsense.com/article/how-to-add-patches-to-slow-pitch-softball-jerseys.html