It has long been understood that Gutenberg's invention depended on a long process of trying out methods and refining them. After Gutenberg, his methods continued to be improved upon, but by the end of the 15th century printing had found the form which it retained until the 19th century.

Gutenberg's main inventions were the printer's ink, the making of type, the use of a press and perhaps most importantly the production process itself which combined these techniques to produce printed books. Each invention would have been useless without the vision which combined new and old methods. Part of the process was composition and once the sheets had been printed they had to be made into gatherings.

The surviving copies tell us how Gutenberg and his team learnt about the work processes and their financial implications as the work went on. They made at least three changes during the printing.

Printing could not have been an economic success without paper, which was originally invented in China and then spread west reaching Europe via the Muslim world. Before this European books were written on vellum, animal skin. One of the British Library's copies of the Gutenberg Bible is printed on vellum.

We can also estimate how many copies of the Bible Gutenberg printed.