ALL papers may be divided into three classes : -
Satin Papers, of which either the whole ground, or the pattern, or both, are of a polished lustre, having somewhat the appearance of satin. They are made by painting the paper over with the required colour, mixed with Spanish white, etc., after which it is polished with a burnisher. Or the colour is mixed with plaster of Paris, laid on, sprinkled with powdered French chalk, and then rubbed over with a hard brush to give the appearance of satin.
Satin papers are very susceptible to damp, even from the paste used in hanging them; they require to be hung with care, on dry walls, and should be protected by a lining paper. When once hung, if thoroughly dry, they can be kept clean for a long time, as the smooth surface of the paper prevents dust and dirt from adhering to it.
Flock Papers, the design on which is formed by the adhesion of flock sheared off from the surface of woollen cloth. The pattern is first printed on the paper in size, next in varnish, the flock is then thickly sprinkled on, and adheres to the varnish, thus forming the pattern.
The pattern on the best papers is printed from wood blocks. The position of each block is guided by four pins in its corners, and a separate block is required for each colour.
Wall papers are printed also in large quantities, and very cheaply, by machinery, the patterns being engraved on metal rollers, one for each colour required, and printed on continuous bands of paper several hundred yards long.
Machine-printed papers are inferior to those printed by hand; the colours of the former often wear off from not being properly set.
Some of the common grained, marbled, and granite papers are roughly coloured by hand, and elaborate papers of the highest class have to be painted by artists.
> Pulp papers can easily be distinguished from others, as the back is of the same colour as the ground of the front.
Hand-printed papers can be distinguished from those that are machine-printed, as the former retain the marks of the pins used as guides for the position of the wood blocks.
Wall papers are sold by the piece, except in the case of borders, which are sold by the yard, or dozen-yards run.
The price varies according to the description and quality of the paper, and the nature of the pattern, an extra being charged for every additional colour included. The introduction of gold or silver in the pattern also enhances the price considerably, in proportion to the amount used.
Down each side of the paper is a blank margin about 1/2 inch wide. In hanging good papers both these margins are cut off, and the adjacent pieces are placed edge to edge. In common papers, however, only one margin is cut off, and the cut edge of one piece of paper overlaps the margin of the adjacent piece.
In these each piece is generally 12 yards long and 21 inches wide. It therefore contains 7 square yards.
After the margins are removed the paper is 20 inches wide.
Each yard in length of the paper then contains 36 x 20 inches = 5 feet superficial, and each piece 12 x 5 = 60 feet superficial.
The number of pieces of paper required for a room is therefore equal to the number of superficial feet to be covered divided by 60.
An allowance of from 1/6 to 1/10 must, however, be made for waste. This allowance is greater for good papers and large patterns than for common papers and small patterns.
Some manufacturers make papers of special widths differing from those mentioned above.
French Papers are made in pieces containing 41/2 square yards. The length and breadth of a piece vary considerably, according to quality, but they often run about 9 yards long and 18 inches wide.
Borders are sold in pieces containing 12 yards, technically known as dozens.
Lining Paper is common uncoloured paper placed under the better classes of paper, in order to protect them against damp and stains from the wall below, and to obtain a smoother surface to work upon.