Table 3 Elemental composition of the grisaille paint layers as determined by LIBS

13–14th

JC012

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Ag, Sr, Ti, K, Ni, Na, CaO

15th (1425–1430)

CG1

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Na, CaO

CG2

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Na, CN, C₂, CaO

16th (1510–1518)

G1

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Zn, Cr, Na, CaO

G3

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Zn, Co, Cr, Na, CaO

16th (1500–1550)

LS01

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Cr, Na, CaO

JC015a

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Cr, Na, CaO

S.José

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Zn, Co, Cr, Sn, Na, CaO

17th (1650–1700)

JC020

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Cr, Na, CaO

JC010

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Ni, Na, CaO

19th (1845–1884)

SS01

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Ag, Sr, Ti, K, Co, Cr, Na, CaO

SS02

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, K, Ni, Cr, Na, CaO

LS05

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Co, Ni, Cr, CaO

20th (1900–1934)

JC007

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Cr, Na, CaO

NC1

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Co, Na, CaO

NC2

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, K, Co, Ni, Cr, Na, CaO

SS03

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, B, K, Co, Cr, Sn, Na, CaO

LS03

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Zn, Co, Cr, Na, CaO

20th (1942–1950)

SS04

Si, Fe, Mn, Mg, Ca, Al, Pb, Ba, Cu, Sr, Ti, K, Co, Cr, Na, CaO

JC003

Si, Fe, Mn, Mg, Al, Ca, Pb, Ba, Cu, Sr, K, Zn, Co, Cr, Na, CaO

20th (1971–1976)

UC3

Si, Fe, Mn, Mg, Al, Ca, Pb, Ba, Cu, Ti, B, Co, Ni, Cr, Na

Unknown

LS02

Si, Fe, Mn, Mg, Al, Ca, Pb, Ba, Cu, Sr, Ti, K, Zn, Co, Na, CaO

LS04

Si, Fe, Mn, Mg, Al, Ca, Pb, Ba, Cu, Sr, Ti, K, Co, Cr, Na, C₂