Figures from McCrone Pigment Analysis?

[Jorge_Stolfi]

I find this analysis particularly interesting: You are not allowed to view links. Register or Login to view.

I have tons of, uh, comments about the McCrone report.  The actual spectra and the microscope images only added to them.  

I hope to write a, erm, commentary of their report some time.  Meanwhile, abut that "clear/white paint".  There are two samples described as such on Table 1, namely samples 12  and 18.

Sample 12 is discussed in the text. It is supposed to come from attached micrograph 11A:
   
I can't see definite sign of any white paint there. The lightest area seems to be just blank parchment, that appears to be white only because it was spared by the light yellow paint.  Maybe that is why the report added "clear/" to the description.  Why not "invisible/"?  The report "identified" sample 12 as "proteinaceous, with a large amount of calcium carbonate present".  Know what else is "proteinaceous, with a large amount of calcium carbonate present"?  Blank parchment...

Sample 18, curiously, is not explicitly discussed in the report. It is supposed to come from the "woman's face" of micrograph 17A is from f70v1, the outer nymph at ~04:00, rotated 120 degrees counterclockwise.  There seems to be no "clear/white paint" on the nymph itself, so presumably the sample was taken from the tiny white rectangle inside the large dark brown area:
     
But that is not "paint".  The size, shape, edge sharpness etc. is quite wrong for that.  A clue to its nature is the round yellow knob that seems to be attached to the NW of that white area.  The glints show that its surface is glossy and knobby.  The material seems to be translucent, as the brown hues of ink show through it. 

I bet a pizza and a beer that the white and yellow object it is a bit of food, specifically of egg yolk and something white like egg white or pastry.   That is, just another food accident, like the "goulash" stain on f102v1+f103r.  

And Table 1 says "Proteinaceous - Carbohydrate - starch (traces)". No calcium carbonate.  I don't put calcium carbonate in my French toast, either.

All the best, --jorge