I want to start a t-shirt line, and I know that I need to turn my illustrations into vector images on Adobe Illustrator in order to have them printed. I have Illustrator and am not completely illiterate in how to use it - but how can I turn my illustrations into vectors without losing their hand drawn look? Say, I make a picture with watercolor, and I want that texture to transfer onto the t-shirt - how would I turn that into a vector without ruining the look of it?