A DICHOTOMOUS METHOD FOR THE CLASSIFICATION OF COLORANT RESPONSES TO LIGHT.

The Colorant Field Guide is an interactive tool designed to aid in the grouping of colorants on paper based on their responses to visible (VIS 400-680nm), ultraviolet induced fluorescence (UVF 420-680nm), ultraviolet reflected (UVR 320-400nm), and reflected infrared radiation (NIR 780-1100nm [850 peak]). By employing standardized vocabularies and metrics like CIELAB and Munsell color systems, the guide ensures rigorous, reproducible, and communicable results. Transparency in documenting light/radiation sources, filters, and post-processing techniques is emphasized to achieve consistency and comparability across institutions. This approach fosters collaboration and enhances the collective knowledge base and ability to communicate transparently about the various colorant responses, while addressing the inherent uncertainties in multispectral imaging and dichotomous identification methods. 

While this tool can be effective for guiding users toward identifications based on observable characteristics, it is essential to recognize the limitations in the identification process. Additionally, any information included that has been cited from other sources is not following the standardized vocabularies or value references as described below.
To determine dichotomous UVR and NIR responses, please refer to the  L* value of your sample from the CIELAB color space.  

DARK: L* ≤ 80
BRIGHT: L* ≥ 81
reference value: X-rite Color Checker Classic A4: L*=96