This paper begins by noting the difference between conservation and restoration, and with the remark that the distinction between the two treatments is often blurred. In any case, the forensic work of a conservator always requires a detailed knowledge of the materials with which he is dealing. At CAL, Smithsonian, conservators and scientist collaborate in the identification of materials, with the conservator outlining the problem and the scientist performing the investigations requiring sophisticated apparatus. The lab director is consulted first, in order to get agreement that the services of a scientist would be worthwhile.