Longish story but someone at work purchased this print 20x30 but the tone wasn't a perfect match to a smaller version of the same print. Contacted the printer, Bay Photo, and the printed a replacement at no cost. The replacement was identical to the first one, talked to Bay Photo again and they were willing to try again but the large format printer is different than the small and it's difficult to match exactly. Had the large and small photos not been hung on the same wall a foot away from each other you would never notice the difference. So ultimately the guy who purchased the print was happy and I got to keep the spare. :). It's printed on aluminum.