Conservators and scientists will occasionally collect tiny microscopic <a href="http://www.artcons.udel.edu/about/kress/examination-techniques-and-scientific-terms/cross-sectional-microscopy">samples</a> from artwork in order to obtain a better understanding of the object's restoration history as well as the original materials used by the artist(s). Samples are often taken in conspicuous areas, such as near regions of existing loss or even along outer edges of a composition. In the case of the Triumph of David, there were multiple old tears and losses scattered throughout the painting allowing for the collection of several paint samples. These samples are then embedded in a clear resin and polished smooth, giving a cross-section view of the paint layers from the ground up under high magnification.<br/><br/>Samples can be viewed in visible and ultraviolet light as both types of illumination can reveal complementary information. Certain pigments may auto-fluoresce under ultraviolet light as well as certain organic materials like varnishes, glues, etc.<br/><br/>Cross-sectional samples subjected to both visible and ultraviolet illumination were prepared by Kristin deGhetaldi (project leader). Samples were imbedded in Extec(R) polyester resin/ hardener (approximately 10/ 0.5 ml) and subsequently analyzed under high magnification using a Nikon Eclipse 80i Binocular Microscope (4x, 10x, and 20x objectives) with a Nikon X-cite(R) 120 Mercury Lamp for reflected ultraviolet light. Under ultraviolet light, the samples were viewed using a BV-2A cube (excitation wavelengths between 400 and 420/ 470 nm barrier filter). Digital images were obtained using the Digital Eclipse DXM 1200f Nikon Camera in conjunction with the Automatic Camera Tamer control software for PC systems.