Fig. 6
From: Out of the blue: Vermeer’s use of ultramarine in Girl with a Pearl Earring
a Visible light image. Photo credits: René Gerritsen Art & Research Photography. b MA-XRF map of calcium. c–j Paint reconstructions with ultramarine (lapis lazuli, Kremer), chalk and yellow lake (weld on chalk/alum substrate) in different proportions (vol%). The paints were applied with a paint applicator (50 and 100 µm thick films; 100 µm films shown in c–j) and a broad and fine brush onto black and white sealed opacity charts