Fig. 1From: A study of the deterioration of aged parchment marked with laboratory iron gall inks using FTIR-ATR spectroscopy and micro hot tableChemical structures of a gallic acid, b ellagic acid, c iron (III)—gallate complex proposed by Krekel [32] and d iron (III)—gallate complex proposed by Wunderlich [33] (see main text)Back to article page