Table 1 Summary of pigments and other materials used in The Blue Room and in the hidden portrait

Ground^f

Lead white (2PbCO₃∙Pb(OH)₂)^a,b,d with gypsum (CaSO₄·2H₂O)² filler^b

Fillers

Barium white (BaSO₄)^a,b,c,d; silica (quartz) (SiO₂)^a

Blue

Prussian blue (Fe ₄ [Fe(CN) ₆ ] ₃ ) ^a,b,d

Ultramarine (synth.) (Na_6-10Al₆Si₆O₂₄S_2-4)^b,e

Prussian blue (Fe ₄ [Fe(CN) ₆ ] ₃ ) ^a,b,d

Black

Carbon black (C) ^b

Bone black (C+Ca ₃ (PO ₄ ) ₂ ) ^a

White

Zinc white (ZnO) ^a,b,d

Zinc white (ZnO) ^a,b,d

Lead white (2PbCO ₃ ∙Pb(OH) ₂ ) ^e

Green

Emerald green

(3Cu(AsO₂)₂·Cu(CH₃COO)₂)^a,d

Viridian (Cr₂O₃·2H₂O)^a,d,e

Compound green-chrome or cadmium yellow mixed with Prussian blue and bone black

Yellow

Chrome yellow (PbCrO ₄ ) ^a,b,c,d

Cadmium yellow (CdS)^a,b,d

Chrome yellow (PbCrO ₄ ) ^a,b,c,d

Red

Vermilion (HgS)^a,b,d

Other

Acrylic resin varnish (from later conservation treatment)^c