14-03-2026, 07:58 PM
(14-03-2026, 06:39 PM)Jorge_Stolfi wrote: You are not allowed to view links. Register or Login to view.(14-03-2026, 02:31 PM)LisaFaginDavis wrote: You are not allowed to view links. Register or Login to view.There would not have been any way to determine the elemental composition of the inks and pigments before about 1970
Actually there would have been chemical means capable of that, since the 1800s. They would need much bigger samples than what McCrone's X-ray tools neeed. Like scraping away a 5x5 mm area of paint. But they would have given as much information as the McCrone report did: the blue pigment is azurite, the green pigment is some organic compound of copper, the red pigments are hematite or lead oxide, etc.
Even for the text and outline inks, an 18th century chemist may have been able to give a better identification than McCrone did.
True, Jorge, and I pointed to this in a previous comment:
The Spotted Unicorn Knocking on Your Door wrote: Look, for instance, at Albert Osborn's 1908 book, "Questioned Documents": You are not allowed to view links. Register or Login to view. In it, Osborn describes some quite sophisticated methods for the detection of forged inks
I plan to download that sucker and devour it.
Rich.

