Two modes of making articles of papier-mache are adopted: either by gluing or pasting different thicknesses of paper together, or by mixing the substance of the paper into a pulp, and pressing it into moulds, (a) The first mode is adopted principally for those articles, such as trays, in which a tolerably plain and flat surface is to be produced. Common millboard, such as forms the covers of books, may give some idea of this sort of manufacture. Sheets of strong paper are glued together, and then so powerfully pressed that the different strata of paper become as one. Slight curvatures may be given to such pasteboard when damp, by the use of presses and moulds. Articles such as snuff-boxes are made by gluing pieces of paper cut to the size of the top, bottom, and sides, one on another, round a frame or mould, which is afterwards removed. Articles made of pasteboard have a fine black polish imparted to them in the following manner: - After being done over with a mixture of size and lampblack, they receive a coating of a peculiar varnish. Turpeutine is boiled down until it becomes black; and three times as much amber in fine powder is sprinkled upon it, with the addition of spirit or oil of turpentine.
When the amber is melted, some sarcocolla and more spirit of turpentine are added, and the whole is well stirred. After being strained, this varnish is mixed with ivory-black and applied in a hot room, on the papier mache articles, which are then placed in a heated oven. Two or three coatings of the black varnish will produce a durable and glossy surface, impervious to water.
(6) Papier-mache, properly so called, is that which is pressed into moulds in the state of a pulp. This pulp is generally made of cuttings of coarse paper boiled in water, and beaten in a mortar till they assume the consistence of a paste, which is boiled in a solution of gum arabic or of size, to give it tenacity. The moulds are carved in the usual way, and oiled, and a pulp is poured into them, a counter-mould being employed to make the cast, nothing more than a crust or shell, as in plaster casts.. In some manufactories, instead of using cuttings of made paper, the pulp employed by the paper-maker is, after some further treatment, poured into the moulds to produce papier-mache' ornaments.
It has now, in some cases, superseded the carved and composition ornaments employed to decorate picture and glass frames; but it is in the ceilings and walls of rooms and the interiors of public buildings that papier-mache is found most valuable. Plaster and composition ornaments are ponderous; carved ornaments are costly; but those of papier-mache' are light and of moderate price. Maps in relief are also occasionally made of papier-mache'. Paper roofs have been occasionally used. Sheets of stout paper are dipped in a mixture of tar and pitch, dried, nailed on in the manner of slates, and then tarred again; this roof is waterproof, but unfortunately very combustible.
Paper. Casts from the Antique. - This method of obtaining facsimiles of sculpture in basso-relievo is very easy. Stiff, unsized, common white paper is best adapted for the purpose. It should be well damped; and, when applied to sculpture still retaining its colour, not to injure the latter, care should be taken that the side of the paper placed on the figures be dry - that is, not the side which has been sponged. The paper, when applied to the sculpture, should be evenly patted with a napkin folded rather stiffly; and, if any part of the figures- or hieroglyphics be in intaglio, or elaborately worked, it is better to press the paper over that part with the ringer. Five minutes is quite sufficient time to make a cast of this description; when taken off the wall, it should be laid on the ground or sand to dry.
Composition for Picture Frames - . Mixing. - The principal ingredients are, glue, water, linseed oil, rosin, and whiting, which are combined in such proportions as to make a mixture soft enough for working, while, at the same time, it papier-mache 147 should be so tough as not to crack, and should harden in a few hours if the ornament be thin, or in a day or two if it be more massive. The state in which it is used by the ornament maker is that of a stiff dough; and the making of it resembles the process by which the baker makes his dough. The proper amount of glue is steeped in water, which is heated to dissolve the glue; while the .oil and rosin are melted in a separate vessel, and then poured into the vessel containing the melted glue. The whiting is pounded, and placed in a tub or pan - being previously warmed if the weather be damp and cold - and the hot melted glue, oil, and rosin are poured upon the whiting, and then well mixed tip with it, and kneaded, rolled, and beaten until it becomes a smooth, tough, elastic kind of dough or putty.
It may then either be used at once, or may be laid aside for future use; but, whenever it is used, it must be warmed, either before a fire or by admitting steam to act upon it, because, when cold, it is too hard and stiff for use.
The manner of using this composition is to press it into moulds; the preparation of which is the most important part of the business; it is generally done by men who are not engaged in making the ornaments themselves. The moulds are usually made of boxwood, which, by its smoothness of grain, permits very fine figures to be cut in it, and is very durable. The mould carver has to proceed with his work in an opposite way to the ordinary carver; for he must make depressions or hollows instead of raised projections, and projections instead of hollows. The mould carver makes his mould look, in every part, directly the reverse of what he wishes the ornament to appear.
The block of wood being planed and smoothed, the carver draws on its surface a representation of the object which he wishes to carve, and then proceeds to work out the minute details. The tools used in this carving are exceedingly fine and sharp, some of them not exceeding 1/40 inch in width. These are, as in common carving, mostly gouge*, with various degrees of curvature. The sharpening of them is a matter of great nicety, and in some cases re* quires files made of very fine wire. The block of boxwood is moistened with oil during the process of cutting, in order to facilitate the progress of the tool. The cuts are, in the first instance, made perpendicularly from the surface of the wood, and afterwards varied into the necessary directions to produce the pattern. In order to know how to vary the depth of different parts of the mould, the carver must either be guided by the accuracy of his eye and the correctness of his taste, or he must have another mould of the same pattern before him.
Sometimes moulds are made by casting, the material being brass, copper, pewter, lead, or sulphur. A model, representing the object which it is desired to produce, is made of composition or plaster, and is placed on a flat stone, and surrounded by a raised border .or edging, so that it lies in a cell,or trough. The model is then oiled, and the melted metal or sulphur is poured on it, so as to entirely, cover it. When cold, the raised border is broken away, the mould is taken tip, and the model is removed, from within it.. It is then imbedded in a wooden case to preserve it from injury, and to fit it for the better reception of the composition. Sometimes brass moulds are made in this way, and afterwards chased; that is, the minuter details of ornament are cut, or rather scratched, by very fine tools. When, the mould, whether of wood, metal, or sulphur, is to be employed to cast ornaments, it is brushed over with oil, to prevent the adhesion of the composition. A piece of composition, large enough for the intended purpose, is then taken up in a warm soft state, and pressed into the mould by the hand.
A wet board is laid upon the surface of the composition, and the whole is put into a powerful screw-press, by which the composition is pressed into every part of the mould, however deep and minute it may be. The same pressure-makes the upper surface of the composition adhere to the wetted board, so that, when it is taken out of the press, the mould may be pulled off the ornament, leaving the latter adhering to the board. When the cast has become a little hardened, it is cut, or rather sliced off, with a broad knife, to the required thickness.
The composition ornament, thus made, is exceedingly pliant and supple, and may be bent into almost any form without breaking or injuring it; it is this property which makes these ornaments so convenient; as they may be applied to the round, the flat, or the hollow parts of a frame, with almost equal ease. They are fixed on either with glue, or, if quite soft and warm, with hot water, which, by softening the glue contained in the composition, produces a sufficiently strong cement; and, in a short time, they become sufficiently firm and hard to be handled without injury. In modern frames which are intended to imitate antique carved frames, the manner of laying on the various pieces of ornament requires much care in the workman. If an antique frame, or a drawing from it, is given to the ornament maker to imitate, he must have moulds carved of all the various parts, so that, when united on the frame, the assemblage of composition casts may present a facsimile of the frame. If he wishes to produce a frame which shall possess a general resemblance to old patterns, but without tying himself down to any individual pattern, he has to depend on his taste and judgment, both in the cutting of moulds and in the disposition of the various pieces of ornament on a frame.
This composition, being a compact substance, is heavy. In this point carved ornaments have a great superiority over composition; indeed, the heaviness of the latter was one reason which led to the adoption of papier-mache ornaments. .When papier-mache ornaments are used, they are cast in moulds, resembling those just described. The paper is in the state of a pulp; but there is this difference between the two kinds of ornaments. The pulp is pressed between two moulds, so that the thickness of the ornaments is seldom more than about 1/4 inch at any part; thus the ornament is of less weight, and there is a saving of material.