A puzzle or not?

"Scientists have settled one of the great puzzles of pre-Gutenberg commercial publishing." 

This is how the article opens in the Guardian, so I sat down to read it. 

"Pocket Bibles, painstakingly inscribed by hand in their tens of thousands in the universities of Paris, Oxford and Padua, were made of vellum taken mostly from the hides of calf, sheep and goats, and then made ultra-thin by a process still unknown."

The article goes on for several paragraphs, but right at the end I discovered that the researchers had "found evidence for the equivalent of a set of 13th-century Europe-wide industry standards, defining the raw material for a labour-intensive copying system that published at least 20,000 Latin pocket Bibles for an eager market. But the technology remains elusive."

So they haven't solved the puzzle at all.  Surely we already knew it was mainly calf skin, with a some sheep and goat skins? The article goes on:

 “It was a craft industry where the skills have been handed down from father to son, and stay within families, and we don’t know how they did it anymore,” Experiments with descriptions found in medieval literature proved unhelpful.

“Clearly the people writing about them weren’t the people doing them: they heard at second hand. As a consequence they write things down which aren’t genuine recipes for parchment production.”

I might be forgiven for thinking the journalist who reported this in the Guardian is guilty of the same thing. The puzzle has not been solved.

Se the article here: http://www.theguardian.com/science/2015/nov/23/scientists-get-under-skin-13th-century-mystery-vellum-vulgate-bible