Art fraud is a problem in Canada. Some collectors do not use reputable dealers, nor have an attribution confirmed. If the authenticity of a painting is suspect, scientific testing can be considered. The Analytical Research Services at CCI (Canadian Conservation Institute) receives many requests for help, although scientific examination is only useful in cases where materials can be compared to information already available about the artist or period concerned. Of those tested at CCI, the paint on a van Gogh was too soft, and contained titanium white (not available before 1938), and a Rembrandt print was on wove paper (not invented until after his death). A valuable Rubens could not be authenticated when recovered years after its theft, as analysis showed some paints were post-Rubens. Infra-red photography and x- radiography proved that the signature on a Monet replaced one which had been removed. A group of five paintings attributed to Chagall, Miro, and Kandinsky were all found to have a similar alkyd resin medium (one not normally used by artists), stains with identical components, similar grounds, and were similarly stapled, not tacked. Because of years of research in Britain, America, Germany and CCI, much reference data is now available for comparison in some areas, but much more has to be done. -- CCI