In order to obtain a smooth surface to work upon, a plain coarse white " lining " paper is sometimes hung first. In hanging lining papers the edges of adjacent pieces overlap about ½ inch, and are distempered, and well rubbed down, to prevent their showing through the wall paper. Common papers are hung with their trimmed edges facing the light, so that they may not cast a shadow. Good papers are hung edge to edge.1 Where the walls are damp, and battening with lath and plaster would be too expensive, canvas may be stretched tight, and nailed to battens, to receive the paper; it is, however, generally unsatisfactory, as it expands and contracts with the changes in the weather.
1 In ceilings the edges of the paper should run at right angles to the principal light in the room.
In re-papering walls the old paper should be removed, the walls scraped, washed, stopped, and coated with size; or, if the old paper is left on, a coat of size may be applied to it, and then over that a coating of whiting and size or distemper.
There is considerable danger in leaving the old paper upon the walls, and it should never be allowed, as the paste which secures it is apt to become decomposed and injurious to health.
"Indiarubber, gutta percha, laminated lead, and tinfoil papers ' have been used as lining papers for walls where damp would be likely to injure the paper; but all these are now superseded by the papers made by the Willesden Waterproof Paper and Canvas Company, 34 Cannon Street, London, which are much cheaper, and may even be used by themselves, being supplied in certain colours besides admitting of being coloured.' The drying of walls may be quickened by rubbing them over with sulphuric acid." 1