12 mordanted and cochineal dyed modern wool samples were subjected to scanning electron microscopy and energy dispersive x-ray spectrometry analysis. The analyses for metallic elements matched in all cases those actually used in the preparation. The mordants detected contained the metallic elements: aluminum, chromium, copper, iron and tin. SEM photomicrographs were also examined for the effects of mordanting on fiber surfaces. Atomic absorption analysis of the samples is also reported. -- ICCROM