Avery Bazemore
FTIR assignment
Summer term 2015
Using ATR-FTIR, I analysed a fragment of brown calf leather from the spine of a book
bound in 1826, a piece of new repair calf from Hewit dyed to match, and a piece of new
undyed repair calf.
Leather from 1826 book
New calf dyed a similar color (no fixative)
New undyed calf
The new leather has some peaks which are less prominent in the old leather, and is more
jagged in general, but especially to the left of the double bond peak, in the area characteristic
of triple bonding. This could be because it has deteriorated, because the new leather is
tanned using different chemicals, because the old leather had been fed or coated, or it could
just be noise due to the smaller sample. An ash test determined that the new leather is
partially chrome-tanned, which was not invented until 1858. The dyes are also undoubtedly
different. The dyed new leather has more peaks at the far right than the undyed, probably
the result of unusual elements in the dye. The fragment of old leather was much smaller, and
missing the grain layer, which might have distorted the result. It transmitted far more light,
giving a much fainter signal. The highest peak on the old leather was around 91%
transmittance, but the highst on the new leather was 76%.
The new leather samples were both matched most closely with vegetable-tanned leather in
the library, but the old leather matched surprisingly closely with black bookcloth.
1826 leather (black) vs “Bookcloth Black” (red), 79% match
New dyed leather (black) vs “Vegtan with Cl flesh” (red), 83% match
New undyed leather (black) vs “Vegtan with Cl flesh” (green), 87% match