The role of smalt in complex pigment mixtures in Rembrandt’s Homer 1663: combining MA-XRF imaging, microanalysis, paint reconstructions and OCT

Heritage Science

Table 2 Lab* data of paint-outs applied on white and black supports. ΔLab* is calculated to be used as an indication of the translucency of the paint

	On white support			On black support			Differences (Δ) (e.g. ΔL* = L_w − L_z)
	L*_w	a*_w	b*_w	L*_b	a*_b	b*_b	ΔL*	Δa*	Δb*
Paint-outs with 2.7 wt% CoO smalt, earths, lakes and boneblack in linseed oil
x5 cap	24	1	3	25	1	3	1	0	0
x6 cap	29	2	5	29	2	5	0	0	0
x56 garment	26	4	5	29	4	6	3	0	1
x57 garment	29	6	8	27	7	10	− 2	1	2
x25 waistband	27	0	0	28	0	1	1	0	1
x34 waistband	31	3	5	30	3	5	− 1	0	0
x28 background	24	2	5	24	2	7	0	0	2
Paint-outs with 4 wt% CoO smalt, earths, lakes and boneblack in linseed oil
x5 cap	25	0	2	25	0	2	0	0	0
x6 cap	29	2	5	29	2	5	0	0	0
x56 garment	30	5	7	31	5	7	1	0	0
x57 garment	30	6	7	29	7	8	− 1	1	1
x25 waistband	26	0	0	28	0	1	− 2	0	1
x34 waistband	30	2	4	28	2	4	− 2	0	0
x28 background	23	2	5	25	2	5	2	0	0
Paint-outs with colorless glass, earths, lakes and boneblack in linseed oil
x5 cap	25	1	2	25	1	2	0	0	0
x6 cap	29	2	6	29	3	6	0	1	0
x56 garment	32	6	9	31	6	10	− 1	0	1
x57 garment	30	8	9	30	7	9	1	− 1	0
x25 waistband	35	6	11	30	3	6	− 5	− 3	− 5
x34 waistband	34	8	10	32	6	9	− 2	− 2	− 1
x28 background	22	2	7	23	2	7	1	0	0
Paint-outs with pure pigments in linseed oil
Smalt 2.7 wt%	35	0	− 27	26	0	0	9	0	26
Smalt 4 wt%	31	9	− 37	24	0	1	7	8	36
Red earth	37	24	19	37	25	18	0	1	1
Yellow earth	48	20	42	49	20	40	1	0	2
Kassel earth	24	1	3	25	1	2	1	0	1
Bone black	17	0	2	17	0	3	0	0	1