It is much better and safer to completely back a tapestry than to reinforce it with a lattice work of strips of linen as is sometimes done. Before leaving this subject, a word of warning is perhaps not amiss. Never buy a tapestry without seeing the back of it. The forging of tapestries is a very difficult and expensive process which is rarely indulged in, but the unscrupulous merchant will acquire a few torn and tattered fragments and will have them pieced together with great skill. On the back the difference in technique and in the quality of the thread is apparent.
Where there is a large amount of dust in the atmosphere of a city it is often advisable to cover the tapestries with glass. This is an unfortunate expedient because of the reflection in the glass and because of the expense, weight, and the difficulty of handling large sheets of plate glass. But the greatest danger comes from moths, who find a safe harbor behind the glass. Glazed tapestries should be frequently aired and examined for this reason.
There are numerous methods of cleaning textiles. (See Carlotta Brinckmann: Die Instandsetzung der Raffael Teppiche, Museumskunde, vol. I, p. 34; Die Behandlung Koptischer Stoffe, Museumskunde, vol. II, p. 150. Böttiger and Köhler, Uber die Pflege gewirkter Teppiche, Museums-
