If the walls are quite new and smoothly finished, the only preparation usually necessary is to lay on a turncoat of weak size, the use of the size being to make a surface to which the paper will stick better than to the bare wall. In preparing an old whitewashed or coloured wall for paper, the wash or colour is wetted with water and scraped off with an old plane-iron, or any piece of steel which has a smooth edge, after which the wall should be swept down with a stiff broom, to remove all that the scraper may have left, and make an even surface. If there is any loose plaster, those parts should be well sized and have a piece of thin strong paper pasted over them; but the best way is to get the place replastered. Cracks or holes may easily be filled with a little putty; in no case should they be left. If not stopped in any other way, slips of paper should be pasted over them, or else the cracks will soon show through the outer paper. After all this is done, the room may be sized, and the size will be dry enough in an hour for the papering to be commenced. If the room has been already papered, it will be necessary to go over the walls and tear off all the loose pieces, especially at the top and bottom, corners, and edges.
If the bare wall is exposed by the tearing off, these spots should be sized. The walls of rooms finished in a superior manner are generally plastered three coats, and upon the plaster, when quite dry, a coating of lining-paper is laid, to obtain a smooth surface. Sometimes common thin canvas is used instead of lining-paper, and occasionally instead of plaster. In the latter case, battens should be fixed against the walls, to fasten the canvas* to, and prevent it touching the walls. The preparations having been made, the hanging of the paper may be proceeded with: the rule is, that the edges of the paper, when hung, shall be towards the window. The appearance of many a handsome paper has been spoiled from carelessness or ignorance in this particular; but when this precaution is observed, the lapped joints scarcely show. First of all, the edges of the paper are to be cut, and as the hanging is to begin at the window on each side, that edge which is -cut close for one side must not be cut close for the other.
This point being decided, unroll a yard or two of one of the pieces of paper, cut the edge, unroll a yard or two more, roll up loosely the part that is cut, and continue till the end is reached, when the process being repeated with the other edge, the piece will be at last rolled up again as it was at starting. Not more than about 1/4 inch of paper should be left at the edge which is not cut close. If there is a back and a front window in the room, the same rule must be observed, and the finish will come in the corner most out of sight, by the mantelpiece, or at the back of the folding doors. When the edges are finished, the paper is to be cut into lengths, about 1/2 inch longer than the height of the room; but they must be cut so that the second will match the first, and so on. There are certain dots or marks on the edges which show where the match is, and if the length required comes between these dots, the portion down to the next dot must be cut off after each length, which will bring the match the same as where it started in the first length. Care should be taken to cut straight across, and as many lengths may be cut as will be sufficient for two sides of the room. These are to be turned all together the plain side uppermost, and the first one may be pasted.
If the paper is thin and common, it must be put on the wall immediately; but if of good quality, it is to be left to soak for two or three minutes, while for a stiff glazed or flock paper, from five to eight minutes would not be too much. The reason is, to give time for both sides to become equally damp, otherwise there is no certainty that the paper will stick. The first length is to be put up with the close-cut edge close to the woodwork round the window. Having brought the top to meet the ceiling, see that the length hangs straight, trying it if necessary by a plumb-line, then taking it by the lower end, lift it away from the Wall all but about 3 inches at the top, then let it fall, and it will drop into its place without a wrinkle. Now With a soft clean cloth begin at the top and press the paper to the wall all down the centre to the bottom, then beginning from the top again, press it from the centre to each side alternately, regularly downwards. If this operation be properly done, the length will be perfectly close to the wall and smooth in every part. It is not to be pressed heavily; but the cloth being taken in the hand as a round loose lump, must be moved quickly over the surface - dab - dab - dab - with a light and clean touch, otherwise some of the colours will be apt to smear.
Last of all, mark with the end of the scissors where the paper meets the skirting, cut off all that is over, and press the end carefully into its place. Proceed with the second length in the same way, bringing the close-cut edge to meet the pattern of the first one, and taking care that no gap is left between. Neglect of these precautions will convert a handsome paper into a sight that will be a constant eyesore. Try the lengths frequently with the plumb-line to avoid the chance of getting out of upright, and remember that the outside end of the piece is always the top of the paper. Paste is best made with old flour, water, and a little size or glue; alum is also added to paste to make it spread more freely without losing any of its tenacity or sticking quality; it should never be used while warm. The paste should be rather thicker than ordinary gruel, and laid on smoothly and equally, not putting too much, or it will squeeze out at the edges. Where this takes place, it must be removed with a clean damp sponge: any accidental smears of paste may be removed in this way, if taken off lightly as soon as they are made.
Decorative paper for covering the walls of rooms is manufactured in "pieces," which are 12 yards long and 20 inches wide.