[JustinD]

Originally Posted by packs

Shouldn't the image be reversed?

Most would think that, but the answer is no.

this is a snipped quote explaining offset better than I can briefly:

"Most commercial printers nowadays use a technique called offset printing. Instead of the printing plate directly applying the ink to the paper, the plate transfers the ink to a rubber cylinder which in turn applies the ink to the paper. So instead of pressing the plate down on the paper to print the card, three cylinders roll along to do the printing. One cylinder has the print plates, one transfers the ink to the paper and a third pushes along the paper through the press. This method is the cheapest way to produce a large number of high quality images. The plate doesn't wear out as fast because it's not coming in contact with the paper and the rubber cylinder makes better contact with the paper than a metal cylinder ever would.

So why is the press plate not reversed? Well, it's true that when transferring the ink to the paper the image has to be reversed so it prints properly, but the image is reversed when the plate transfers the ink to the offset cylinder. If the image was reversed on the press plate it would be correct on the offset cylinder and when the ink transferred to the paper it would be reversed again."

Ben is correct also that some plates are still reversed if they use a direct printing process like direct litho. Most modern cards now are offset though for cost savings.