Pigments
Reference samples of painting materials (especially pigments and binders) used in ALMA Laboratory for the testing of analytical methods and creation of reference libraries can be divided into three categories – (i) purchased from commercial suppliers, (ii) hand-collected at historical mining sites and (iii) experimentally produced in laboratory to replicate production according to old recipes. Search for historical sources of raw materials for painting as well as verification of historical recipes is an integral part of ALMA's long-term strategy. Subsequently, comparison of relevant reference samples with samples from actual paintings is used for provenance studies.