Reference samples were purchased from major artist materials manufacturers and suppliers1. A complete list of manufacturers whose materials have been investigated until now can be found below. This list will be updated periodically as new materials from various other art supply manufacturers are analyzed and included in the database.
Up to this moment most of the reference samples included are pure materials, but the database covers some mixtures of pigments and some binder-pigment mixtures as well. It is our intention to expand the number of available reference samples and to enrich the database with more types of mixtures (e.g. binder-pigment, pigment-pigment, pigment-dye) in the nearby future.
The INFRA-ART database is state-of-the-art spectral library that provides not only high-quality spectral data but also detailed information for each investigated reference material. The database metadata descriptors for the reference samples are structured as follows: sample ID (a unique identifier), record name, sample type, sample source, origin, description, alternative names, chemical information, history of use, and material class.
Samples were inserted within the database by giving them a unique sample ID (e.g. pigments obtained from Kremer Pigments are denoted by PK followed by the catalog number). The record name equals the commercial name given by the manufacturer. For each entry, we also included additional information such as sample source (e.g. Kremer Pigmente), origin (e.g. natural mineral), sample description (e.g. powder sample), alternative names (historical names, color index code), chemical information, material class (e.g. mineral pigment), and history of use (the period or year of introduction into use). If provided by the manufacturer, provenance information was included as well within the origin field2. Metadata related to the employed techniques (type of equipment) as well as related to the experimental conditions (data acquisition conditions) are also available for each record.
1 What about historical pigments? The manufacturing process of art materials has changed dramatically over time. However, some of the current art manufacturers and suppliers still use for some of their premium products traditional manufacturing techniques. In many cases information regarding the origin/provenance of the raw materials is also provided. Depending on the availability we included also some raw mineral pigments within the database and we hope to extend these types of samples in the future. Of course, historical pigments are of utmost importance and we hope to have some collaborations in the future with other institutions that have collections of historical pigments.
2 Some of the mineral pigments available in product catalogs come from important geological centers of pigment extraction and production in Europe, well documented since antiquity. Whenever specified by the manufacturer we included this data as metadata related to the investigated sample.
