Table 2 Summary of samples, analytical techniques and identified materials

P1

black

F1; IR2; R

carbon based pigment, calcite, lithopone

P2

black/white

F1

lithopone

P3

black/white

F1; F2; IR2

lithopone

P4

blue

F1; R

ultramarine blue, calcite, lithopone

P5

pink/black

F1; F2; IR1

iron oxides, lithopone

P6

yellow

F1; IR2; R

monoazo PY3 yellow pigment, calcite, lithopone

P7

dark grey

F1

lithopone

P8

blue/green

F1; IR2; R; PY

ultramarine blue, lithopone, PVAc

P9

yellow

F1; F2; IR2

goethite, lithopone

P10

black/white

F1

lithopone

P11

black/white

F1; IR1; IR2

lithopone

P12

dark grey

-

erratic sample, probably not belonging to the stripe

P13

white/blue

F1; IR1

lithopone

L1

black

IR1

gypsum, calcite

L2

white/green

F2; IR1; R

gypsum, lithopone

L3

blue

F1; IR1; R; PY

PVAc, siccative oil, ultramarine blue, gypsum, barium sulphate

L4

yellow

IR1; R

gypsum, barium sulphate

L5

black

F1; IR1; R

carbon based pigment

L6

white

F2; IR1

gypsum, barium sulphate

L7

red

IR1; R

gypsum, lithopone, toluidine red

L8

orange

IR1; R

PVAc, toluidine red

L9

dark red

F1; IR1; R

PVAc, gypsum

L10

blue

IR1; R; PY

PVAc, siccative oil, ultramarine blue

L11

white

IR1

barium sulphate

L12

green

IR1; R; PY

barium sulphate, gypsum, phthalocyanine blue, monoazo PY3 yellow pigment, PVAc, siccative oil

L13

blue

IR1; R

phthalocyanine blue, calcite, barium sulphate

L14

yellow

F1; IR1; R

monoazo PY3 yellow pigment, lead chromate, lithopone

L15

light green

IR1; R

phthalocyanine blue

L16

light brown

F1; IR1; R

PVAc

L17

resin

IR1; R

PVAc, monoazo PY3 yellow pigment, phthalocyanine blue

L18

green

IR1; R

barium sulphate, monoazo PY3 yellow pigment, phthalocyanine blue

A1

pink/red

F1; IR1; IR2; R

toluidine red, lithopone, gypsum

A2

violet

IR1; R; PY

PVAc, lithopone

A3

blue

F2; IR1

ultramarine blue

A4

green

IR1; IR2; R

ultramarine blue, gypsum, barium sulphate

A5

white

F1; F2; IR1; IR2; R

lithopone, carbon based pigment

A6

blue

IR1; IR2

ultramarine blue, barium sulphate

A7

violet

F1; IR1; IR2; R

barium sulphate, calcite

A8

yellow

IR1; IR2; R

goethite, lithopone

A9

black/white

F2; IR1; IR2

lithopone

A10

white/pink

F1; IR1; IR2; R

lithopone

A11

pink

F1; IR1; IR2

lithopone, toluidine red, calcite

A12

violet/yellow

F1; IR1; IR2; R

goethite, barium sulphate

A13

resin

F1; IR1

PVAc

A14

red

IR1; IR2; R

toluidine red, calcite

A15

resin

IR1; R

PVAc, barium sulphate

A16

resin

IR1

PVAc, barium sulphate

A17

black

F1; IR1; R

toluidine red, lithopone, goethite, carbon based pigment

A18

resin

IR1; IR2; R

PVAc, barium sulphate, calcite,

A19

white

F1; IR1; IR2; R; PY

PVAc, lithopone

A20

yellow/brown

IR1

PVAc, barium sulphate, goethite