And then there is another problem with framed paper prints: the glass. I call the print on metal "garage art" for a reason: its perfect for the garage. No frame to buy, no glass to break. Oh yes, that breaking glass thing. Has it ever happened to you? It did to me just recently:
This was not staged! It actually happened. That door closed a bit too hard and that picture fell to the ground. Broken glass where I drive and park my car is NOT a good thing. Fortunatley of the two framed pictures on that wall only one fell. The print-on-metal above it also stayed up, but if it had fallen there'd be no broken glass to worry about!
The print on metal is noticeably more expensive than the same sized print. The cost to me is noticeably higher as well, and its only natural the extra cost of materials is passed along. But considering there is no frame to purchase, and the peace of mind, and the durability, its a great value when all is said and done.