[annalex]

How does the map prove it?

1450’s: Central Germany
1460’s: Most Germany, Paris, Rome, Venice, Bologna, Naples
1470’s: Same plus England, Low Countries, Spain, whole of France
After that, everywhere.

If anything, the early adopters seems to be Italy, — “hot” temperament and Germany — “medium cold”. The late adopters are likewise “hot” like Spain and “cold” like England.

[Joe 6-pack]

Look at the volume of output. Rome, Naples, Venice - high output early on, but no immediate growth in the area afterwards. Similarly, when you look at things temporally, there's a "pile up" in northern Italy and the Italian alps, with some minor latent activity around the Adriatic, and nothing into the Balkans, or around the Mediterranean rim. Meanwhile, Stocklholm comes into play in the same decade as Antwerp and Vienna, with additional proliferation throught sparsely populated Scandinavia in the subsequent decade(s).

There's been ample scholarship on the dawn of the press and the reformation, to the point I don't think it's really that debateable. I merely added as a corrolary, that the established visual vocabulary of Christian/Roman Catholic and Orthodox iconography held firm in regions where the printing press (and presumably the literacy rate) were delayed, whereas in areas where printing (and presumably literacy) caught hold (and coincidentally, so did much of the reformation), the emphasis on "the Book" lessened the emphasis on the visual as a means and method of religious instruction.

[Joe 6-pack]

Here's a better illustration with the source link:

Literacy - Encyclopedia of European Social History