Plaster and Papier-Maché Ornaments for Rooms.
The mouldings of cornices in rooms are formed by a wooden mould drawn along a straight-edge to guide the mould, acting like the carpenter’s plane, when forming analogous mouldings in wood. When such cornices are of sufficient size and depth to require it, wooden brackets, shaped something like the profile of the cornice, are fixed up against the wall, and laths are nailed on these brackets, to serve as a foundation for the mouldings. By this means the necessity for a heavy mass of plaster, to get the requisite projection in the cornice is avoided; which mass would be unwieldly to manage, and liable to fall down by its weight.
Foliage and ornamental work in plaster is made by modelling the ornaments by hand, in a proper kind of clay, worked by steel or wooden tools, resembling small spatulas in form. To do this requires a taste and skill in drawing or designing in the workman, which raises him to the rank of an artist. When the model is finished and dry, the surface of it is covered with a thin coat of oil, and a mould of fine plaster is taken from it in separate pieces. To allow of the plaster mould being taken off the model, the edges of these separate pieces of the mould are made smooth so as to fit accurately together. From this mould any number of casts may be taken by pouring fluid plaster into the mould when it is put together; and as soon as each cast has set, or become hard, the mould is taken off it, to be put together again for a new cast. There has been recently an improvement introduced, which leads to a diminution of the use of plaster for ornaments; this is by the substitution of papier-maché. The material so named is formed chiefly of paper, brought to the state of a paste, and then compressed in moulds. There is to every ornament so made a counter-mould, following the general contour of the ornament, so that the piece is made about equally thick in every part. The resulting ornament is very much less ponderous than those made of plaster, and much less liable to fracture. The interior decorations of many buildings are now made of this material.