2.2.1. Technical Photography

High-resolution technical images were acquired according to the workflow proposed by Cosentino [11–13]. A Nikon D90 DSLR modified camera with a sensitivity of between about 360 and 1100 nm was used. The camera's white balance preset for VIS photography was created with the X-Rite White Balance Target. The American Institute of Conservation Photo Documentation target was used to additionally finetune the white balance and determine optimum exposure for the VIS imaging. The photographs were shot RAW and further processed by Adobe Photoshop CC according to the standards described by the American Institute of Conservation [14].

VIS and UVF photography at 365 nm were taken with X-Nite CC1 and B + W 415 filters mounted together. NIR photography at 1000 nm, with an additional aim of falsecolour infrared imaging (IRFC), was taken with Heliopan RG1000. UVR photography was achieved with Andrea "U" MK II filter.

A pair of 500 W halogen lamps were used for the VIS and NIR illumination system. The light source for UVF and UVR imaging consisted of two lamps equipped with eight 40 W 365 nm UV fluorescence tubes.

#### 2.2.2. RTI

RTI was carried out according to the workflow proposed by the Cultural Heritage Imaging [15]. The images were processed using Adobe Photoshop CC, followed by RT-IBuilder and RTIViewer software, as proposed by the Cultural Heritage Imaging [16,17].
