Fig. 2
From: Chromatographic analysis of natural dyes in mediaeval Islamic paper
UV–vis spectra associated with lac compounds, probably laccaic acids. The retention time for each spectrum is reported in the panels. a Laccaic acid “1”, recorded in the analysis of laccaic acid standard; b laccaic acid “2”, recorded in the analysis of lac dye bath; c laccaic acid “3”, recorded in the analysis of lac dye bath; d laccaic acid “4”, recorded in the analysis of unmordanted lac-dyed model paper