Fig. 2

Multispectral images of all four phantoms (with from left, crosses in: iron gall ink; carbon ink; red iron oxide and India ink) at 940 nm, normalized, showing penetration down to the third layer
Multispectral images of all four phantoms (with from left, crosses in: iron gall ink; carbon ink; red iron oxide and India ink) at 940 nm, normalized, showing penetration down to the third layer