Ultraviolet marking of beadwork restorations

Linda Roundhill

Abstract

When historic or ethnographic beadwork needs loss compensation, either for stability or aesthetic integration, a problem arises as to how to differentiate the new beads from the originals. Beads from modern sources are often nearly identical to antique beads, and sometimes even re-purposed antique beads need to be employed when no modern matches can be found. Qualitative experiments were conducted in order to find the best way to coat glass beads used for loss compensation with a durable, easy to apply coating that would not change the appearance of the beads except during an ultraviolet light inspection. Results are tabulated and discussed, and case studies presented. It was discovered that there are several synthetic resins durable enough for coating tiny glass beads, which can either be made fluorescent by the addition of the dye coumarin, or indelibly marked after application with the dye from a commercial UV marking pen. In this trial, a well-cured aqueous acrylic dispersion coating marked with the UV pen performed best.