Pigments Checker Standard is a purpose-built reference tool from Cultural Heritage Science Open Source (CHSOS) designed to support technical imaging and non-invasive analysis of traditional artistic pigments. 
Pigments Checker Standard integrates a curated set of historically important pigment swatches—spanning from antiquity through early modern art—prepared on standardized supports to enable consistent scientific analysis, such X-Radiography.

X-radiography is widely used in art examination to reveal underlying structures, compositional layers, and hidden features that are otherwise invisible in visible light. Differences in radiopacity among pigments (how strongly they absorb X-rays) provide critical contrast in radiographs, helping conservators and researchers assess features such as preparatory layers, changes made by the artist, and condition issues like cracks or restorations. The Pigments Checker enables practitioners to directly compare how well different pigments show up in radiographic imaging under controlled conditions, accelerating learning and calibration of X-ray systems.

Prepared with high-quality pigment materials precisely applied on archival supports, the X-Radiography Pigments Checker offers a reliable benchmark for colorant radiopacity and imaging behavior. Users can integrate it into diagnostic workflows alongside other technical tools such as multispectral imaging, infrared reflectography, and XRF spectroscopy to build a comprehensive understanding of material responses across modalities.

This product is especially valuable for conservators, conservation scientists, imaging specialists, and students seeking to refine X-ray technique, interpret radiographic contrast with confidence, and train in radiographic documentation of cultural heritage objects.