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The VMS ink is NOT iron-gall
- The VMS ink is NOT iron-gall
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RE: The VMS ink is NOT iron-gall
Aga Tentakulus > 5 hours ago
When I look at Lisa’s UV image and compare it to yours.
The writing is visible everywhere—in the water stain, near the possible chemicals, and, hmm, even where there’s nothing.
It’s visible in all three places. I can even see it without UV light.
When I look at the writing on the other side, I don’t see any pigments in the ink or on the parchment. The ink is dissolved and isn’t pigmented.
That’s why the ink has migrated through the parchment due to the moisture. -
RE: The VMS ink is NOT iron-gall
Jorge_Stolfi > 4 hours ago
(5 hours ago)Aga Tentakulus Wrote: You are not allowed to view links. Register or Login to view.When I look at the writing on the other side, I don’t see any pigments in the ink or on the parchment. The ink is dissolved and isn’t pigmented.
You can't tell that at this magnification. Not even in the higher magnification images included in the McCrone report (~180 pixels/mm). The solid pigment particles in watercolor or lampblack ink/paint are way too small to be distinguished in those images.
But I think that the particles of the blue pigment (azurite) can be seen,just barely, in the McCrone images of the blue paint:
Those white and dark blue dots in the blue-painted area could be individual particles of the mineral, rather coarsely ground. Which would be consistent with the general "improvised" or even "home-made" nature of the paints (and of the painting instrument -- apparently not a brush but a broad-tip quill pen).
On the other hand, I suspect that the bluish green paint used on most of the leaves may have been a soluble dye, seeing how strongly it shows on the other side of the vellum:
McCrone did not identify that green paint; they only determined it contained copper and was not crystalline, hence not malachite or other mineral, and guessed it would be a salt of some unidentified organic acid (a "resinate" in their words).
My wild guess is that it is copper stearate, which can be made by mixing soap with a copper salt like blue vitriol. It is insoluble in water but should be soluble in turpentine or any other solvent used for oil paints. And it seems that organic solvents like turpentine, unlike water and water-based inks, can penetrate the vellum. I gather that vellum is made slightly water-repellent precisely to prevent ink "flaring" and bleed-through.
The yellowish-green paint seen on the first image above may be a different pigment altogether, or a mixture of that bluish-green paint and some yellow pigment.
By the way, the shiny nearly-black ink at the center of the second image is what I believe iron-gall ink should look like. I could contrast it to the much fainter yellowish-brown trace below it. But that would take me into the forbidden BEEP territory...
All the best, --stolfi -
RE: The VMS ink is NOT iron-gall
eggyk > 3 hours ago
I'm slightly confused. In the interest of actually aiding in this conversation, answers to the following would be helpful:
-Is there a certain way IGI should or should not get absorbed/ bleed through the parchment?
-Is it normal that IGI soaks through to the other side of a sheet of parchment, should it only happen in certain circumstances (such as excess moisture)?
-Should IGI rub off onto pages it is facing once dry?
-When IGI soaks into the vellum, is it really "dissolved", or is it the same chemical structure within a porous material? (like water in a sponge is not dissolved)
If we know the answers to these we can potentially test some hypotheses using image analysis of different pages.
(Today, 03:05 AM)Jorge_Stolfi Wrote: You are not allowed to view links. Register or Login to view.
(Yesterday, 09:57 PM)oshfdk Wrote: You are not allowed to view links. Register or Login to view.The following article shows iron gall ink as nearly transparent in 900-1500nm: ... Quoting from the article:
Quote:The underdrawing materials that become transparent, and are not therefore visible, include red Conte crayon, charcoal and iron gall ink.
Yes, but that is what the article I quoted said too: iron-gall ink remains opaque up to 1200 nm, while ocher becomes transparent by 800 nm. And the VMS ink is already transparent before 940 nm (the longest wavelength used in those images).
All the best, --stolfi
The crux of the issue here is that we have two different studies now with two wildly different ranges for the transparency of their specific IGI. In that second study, it says "nearly transparent in 900-1500nm". Your images clearly also do not show fully transparent IGI, even at 940nm; some of it is still visible. Therefore our observations on the VMS ink is consistent with it appearing "nearly transparent" at 900-1500nm.
Furthermore, the existence of two ranges in two studies implies the possibility of more ranges for more types of IGI in others. The exact composition of the ink clearly matters in this regard. -
RE: The VMS ink is NOT iron-gall
Jorge_Stolfi > 22 minutes ago
(3 hours ago)eggyk Wrote: You are not allowed to view links. Register or Login to view.-Is there a certain way IGI should or should not get absorbed/ bleed through the parchment? -Is it normal that IGI soaks through to the other side of a sheet of parchment, should it only happen in certain circumstances (such as excess moisture)?
No, the surface of vellum is treated to prevent that. Not just for IGI but for any water-based ink or paint.
If IGI soaked into the vellum, the edges of pen strokes would be fuzzy. We see that on page f112r. Note the indentation at the top of the free vertical edge: that indentation may be the very edge of the hide sheet, or of a large hole on it. For that or some other reason, it seems that the surface was not properly treated in an area several cm wide around that indentation. When the Scribe wrote the first line of that page, the characters that fell in that area became fuzzy. He avoided that area on the following lines; now and then he tried to get back into it but ran into the same problem. Only by line 22 or so he could get back to the intended margin
On the other hand, oily ("apolar") liquids apparently can soak into vellum even in goo areas. The "ketchup" sauce stain on pages around You are not allowed to view links. Register or Login to view. and f103r seems to be evidence of this:
The creation of that "artistic intervention" seems to have been a complicated process, which tried to unravel in You are not allowed to view links. Register or Login to view.. There was a big spill of sauce between pages You are not allowed to view links. Register or Login to view. and f103r, and a smaller drop between You are not allowed to view links. Register or Login to view. and f104r. The book apparently was closed without cleaning the spilled sauce, which was squished out into flat roundish blobs. Later the spills were cleaned, and there was an attempt to repair their damage on f103r.
But the relevant point is that apparently the sauce had two components, a reddish orange "watery" one, and a not-so-reddish orange "oily" one.
Looking at the small stain on 103v (or f104r), it seems that the watery component stayed put where it had been squished out, while the oily part soaked into the vellum creating a fuzzy halo around the watery stain. That oily component also bled through the vellum and stained the other side of the folios (f103r and f104v).
The same happened on the big stain of You are not allowed to view links. Register or Login to view. and f103r, except that the oily component that bled through to You are not allowed to view links. Register or Login to view. then ofsetted onto f104r, bled though it to f104v, and even left a faint smudge on f105r. Whereas the watery component apparently stayed put on You are not allowed to view links. Register or Login to view. and f103r (but dissolved the ink on the latter, which came off almost completely when the spill was finally wirped off).
Quote: -When IGI soaks into the vellum, is it really "dissolved", or is it the same chemical structure within a porous material? (like water in a sponge is not dissolved)
IGI is soluble when freshly made, but does not soak into the vellum. Instead it bonds chemically to the vellum; and soon, as the iron in it oxidizes to the 2+ state (as in green vitriol) to the +3 state (as in ocher, rust, hematite, etc), the ink turns into an insoluble black polymer.
Quote:-Should IGI rub off onto pages it is facing once dry?
IGO was used on vellum precisely because that polymer was chemically bonded to the vellum and could not be removed by rubbing or washing. To erase IGI one had to scrape away the surface of the vellum, down to the bottom of its pores.
It could offset to another page if the latter was placed over it when the ink was still wet, of course. But presumably the Scribe was good enough to wait until the ink was dry (if not polymerized) before that.
Quote:The crux of the issue here is that we have two different studies now with two wildly different ranges for the transparency of their specific IGI. In that second study, it says "nearly transparent in 900-1500nm". Your images clearly also do not show fully transparent IGI, even at 940nm; some of it is still visible. Therefore our observations on the VMS ink is consistent with it appearing "nearly transparent" at 900-1500nm.
There is no contradiction. The article I quoted says that ocher becomes transparent by 800 nm, while IGI remains visible up to 1200. The other says that IGI becomes transparent between 900 and 1500. The VMS images show its ink becoming transparent around 850 nm or so.
All the best, --stolfi