Well, I don't sell the work I do. I do make posters and postcards for a school, so I somewhat know about printing and resolutions, but not about selling the work. When I print the posters, I usually print it at 300dpi. But if you want really good quality on your works, especially if you have lots of text, you should not print the image off of photoshop. I heard that the quality of photoshop is not so good. People tell me to import the image into a different program such as Quark for high quality. -Adam