The author discusses several projects in which computers have aided investigations by conservators and art historians. The projects emphasized are: the computer program developed by Marion Mecklenburg and Dr. James Colville which models the effects of moisture on the various layers of paintings on fabric; the use of computerized image processing by John Asmus, Carlo Pedretti and Lord Kenneth Clark to subtract the discolored varnish's spectrally resolved opacity from the image of Leonardo's Mona Lisa; and John Asmus' use of ultrasonic scanning equipment and a computer to locate Leonardo's lost mural in the Palazzo Vecchio. -- AATA