[Conference] Voynich Zoom CFP

[Jorge_Stolfi]

Like Rene says though, when you have pigments available (so more than just black ink), any modern meddling becomes clear upon analysis. Here, there was no such thing. And when something was unclear, the question was "I don't know how exactly this period-appropriate pigment was produced" rather than "this looks modern".

It is not quite like that.

A very incompetent forger would have used paints from an art store, with many pigments that were unavailable in the 1400s.  The blue pigment, in particular, would not be azurite.  The McCrone report would have pointed that out.

A more competent forger would have used only pigments that would have been used in the 1400.  He would have used azurite for blue, and McCrone would have said "check" to that.  But he would have used malachite or some other green mineral for green.  Yet McCrone said "the green pigment has copper, but it is not crystalline, so we could not identify it; we can only say that it is not malachite or any other green mineral."  

And, from the report and from Berabe's talk, it seems that they had never seen a manuscript with a green pigment like that.

So McCrone's test results:
(1) did not determine any date for any paint or ink;  
(2) ruled out an incompetent modern forger,
(3) made a competent modern forger unlikely
(4) made a professional pre-modern (1700s or earlier) artist unlikely.  
What possibilities remain likely?

I suppose that the painter could have been a "semi-competent" modern forger, who got the blue pigment right but goofed on the green one.

But my preferred interpretation is that the painter was pre-modern but a very amateur one, who prepared his paints with original recipes.  He bought some azurite for blue (rater coarsely ground,  would say from looking at the microscope images), because he could not make a blue pigment.  But for green he used some unidentified organic compound of copper (a "resinate", as McCrone called it) which he "invented" himself. Like the insoluble "copper soap" that results from mixing soap and blue vitriol.

All the best, --stolfi