Excavations carried out in the Roman City of Settefinestre (province of Grosseto, Italy) during the years 1980 and 1981 were limited (on account of temporary permits) to 45 day seasons. An experiment was carried out in order to find a material or a combination of materials which, when placed in direct contact with mosaics uncovered there, would offer good temporary protection between excavations. The material(s) would have to be easily removable and reusable. Expanded clay was found to have many of the desired properties, but even it could not prevent tree roots from invading the mosaics. For further information on mosaics, see also 21-854, 21-895, 21-896, 21-927, and 21-962.