Attached Link: http://www.midazo.com/dominos/archive/slammin.html

i used carrara for the renders at the attached link. obviously they were printed. largest dimension was 17 inches, and yes, 300dpi is the industry standard for offset and commercial web printing. i use a really mechanical, basic way to figure out what size i need to render to. if the above posts dont answer your questions, just e-mail me and i can tell you what i do. :m