If the wall be new it will require sizing before the paper is put on, though this is by no means done as a rule. If the wall has to be re-papered, it must be stripped of the old paper, or should be stripped, as new papers are too frequently hung upon old papers; a procedure which is certainly not cleanly, and is in many cases prejudicial to health, because the dampness caused by putting up the new paper often detaches the old paper from the surface of the wall, and oftentimes, if the paste used in hanging the old paper has been bad, a fungus is generated, which spreads over the wall in dark patches of a brown or greenish color.

In re-papering a room after any one stricken down with some infectious disorder, such as scarlet or typhus fever, on no account should the old paper be left on the walls, but it should be carefully stripped and the walls washed, and the ceiling coated with limewash, after the old coating has been taken off with clean water. As soon as this is done, the walls may be sized and the process of re-papering may be proceeded with.

Size is a kind of weak glue, made from the clippings of parchment, glove-leather, fish-skin, and similar substances, by boiling them down in water. When cold it resembles jelly. It is sold by all oil and color dealers.

The wall being sized, it is necessary to determine what tools are absolutely necessary for the paper hanger's work. These may be summed up as a pair of boards connected by hinges, or, if preferred, simply grooved and tongued together, or even joined by dowels or pins. The amateur need not provide himself with a pair of boards and trestles merely for the sake of papering a single room : a kitchen table, if long enough, or even a dining table suitably protected, will answer every purpose. The boards are portable, and, therefore, useful to the regular paper-hanger, who may not find any suitable table at the house to which he is going. They are also of greater length than most tables, which is obviously an advantage. Whether the amateur is provided with boards or not, he must of necessity have a pair of good-sized scissors; a pail to hold his paste, whether of wood or iron it matters not, so long as it is clean; and a paste brush, something similar to that used for whitewashing, but smaller.