For those who take the 5 days training course it is provided a free Pigments checker. This is a collection of swatches of 54 historical pigments that have been applied using gum Arabic as a binder on a cellulose and cotton watercolor paper, acids and lignin free, commercialized by “Fabriano”, 270gr/m2. This paper is not treated with optical brighteners, it’s slightlyUV Fluorescent, and it reflects IR. Two cross-hair lines, 0,2 mm (vertical) and 0.4 mm (horizontal), were printed on each swatch of paper before the application of paint, in order to have a means to evaluate the pigment transparency in the IR and IRR imaging. The pigments were mulled into the binder which was added as needed for each pigment and applied with brush. The table below shows the list of pigments used. Among all the pigments and their varieties ever used in art these pigments collection is not exhaustive but it attempts, at least, to be a selection of the most used ones from antiquity to early 1950’. A swatch of just gum Arabic is added as a reference for the binder. This Pigments checker was published on: A. Cosentino “Identification of pigments by multispectral imaging a flowchart method” Heritage Science, 2:8, 2014.