Turning Leather Black
Additional information on both assumptions that I have made and processes in rendering materials for the dye process are available separately within the Assumptions and Terminology and Rendering Dye Materials pages.
Source material and interpretation of methodologies
Original Treatises on the Arts of Painting1 contains a formula for creating black ink that I found very interesting and is relevant to the creation of the formula that I used. A screen capture is below, but the actual text is also available for online reading on Google Books.
Now, according to Encyclopedia Britanica2, vitriol itself is a reference to sulfuric acid, but "roman vitriol" in particular is a reference to cupric (copper) sulfate. This would make a green patina that's still used today, but in my case, I was interested in the ferrous (iron) sulfate properties in a similar manner in order to make what I've found to be called "vinegaroon" in modern leather use.
The process behind making the solution is very simple. In the notes above, you'll see references being made of soaking pounded galls in water, wine or vinegar. This process is used to actually pull the tannins out of the galls, more or less the same stuff that's used for tanning leather in the case of vegetable tanned hides. Now, the interesting part to me was that they had actually figured out they could pull color from tossing in the metal sulfates into the mix.
Constructive feedback is both welcome and appreciated, please let me know if I missed some pertinent information or if there's somewhere I can improve.
As always, thanks for reading!
- Original Treatises on the Arts of Painting by Mary Merrifield.
Contains several references to pigments from the 15th century manuscripts of Jehan le Beague.
The screen capture above is in reference to page 60 of the Manuscripts of Jehan le Gegue.
To read online in Google Books, click here.
- Encyclopedia Britanica, entry about what vitriol is.