I am professional T-shirt designer, fashion designer and print designer with experience of 7 years in same field. I have worked with Amazon merch and many more sites like that for clients so i am aware of all the thing to keep in mind like copyright and original work. i use my own design and keep in mind of licence fonts and copyright stuff so it won't be an issue for you . I have knowledge of photoshop illustrator and corel draw. i make design fast and way soon like i can design more then 20 design a day as i work 12 hours a day Kindly find link of my portfolio. http://manikarnikagraphicdesigner.strikingly.com/#t-shirt-and-print-design