T-shirt design involves drawing out a design on a blank t-shirt. If you want to design your t-shirt, one of your most important investments will be the project's software. These days, t-shirt design software can provide you with the tools you need to create professional-quality custom t-shirts yourself. In the past, if you wanted a unique, one-of-a-kind t-shirt, you generally had to pay to have it professionally designed and printed.
