<a href="http://www.artcons.udel.edu/about/kress/examination-techniques-and-scientific-terms/x-ray-fluorescence" title="_blank">X-ray fluorescence (XRF)</a> is a non-destructive technique that provides elemental information (generally for elements that have an atomic weight above aluminum) that is representative of an artwork's surface. When applied to paintings, XRF can identify the presence of certain pigments (inorganic materials) using an x-ray energy source to help answer questions relating to authenticity and provenance. As the technique does not require sampling, XRF is an excellent preliminary method that can be used to help determine whether additional sampling is necessary. Today XRF units can be found in museums and institutions worldwide, with nearly 1500 units being used for cultural heritage applications.<br/><br/>Care should be taken when interpreting results as peaks can arise from other sources (such as the instrument itself): therefore consultation with a conservation scientist is essential. Other complications such as the use of metal driers (e.g. driers containing lead or manganese), pigments in underlying paint layers, and mordants present in organic colorants (e.g. Ca, Sn) can lead to misinterpretation. While the technique is relatively easy to perform, data interpretation is often more complicated and requires familiarity with both the artwork and the system being used.<br/><br/>A Bruker Handheld Tracer-III XRF spectrometer was used to collect the XRF spectra from various locations (spectra obtained by Kristen Watts and Dr. Amanda Norbutus from Villanova's Chemistry Department; interpretation by project leader Kristin deGhetaldi).