Tag Archives: Physics

Seeing What Lies Beneath Paintings

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By Brett Liem and Michael Robertson Last year we published a short article in Active History where we described optical techniques for recovering the contrast from faded documents.  A range of light sources from ultraviolet (UV) to near-infrared (NIR), filters, and a camera adapted to form images with light outside or the normal visible spectrum were used to reveal residual… Read more »

Recovering Contrast in Faded Documents

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By Olivia Raiche-Tanner, Annika Vetter and Michael Robertson It sometimes happens that ink used in the preparation of documents will fade resulting in reduced contrast between the ink and substrate (paper, parchment, pottery, etc.), often to the point where the writing is no longer readable.  Ink fading can be caused in several ways including exposure to light, chemical reactions between ink… Read more »