Papering is usually figured per roll, put on the wall. The paper is generally 18 in. wide, and is in either 8-yd. or 16-yd. rolls. On account of waste in matching, etc., it is difficult to estimate very closely the number of rolls required, but an approximate result may be obtained as follows: Divide the perimeter of the room by 1 1/2 (the width of paper in feet); the result will be the number of strips. Find the number of strips that can be cut from a roll, and divide the first result by the second; the quotient will be the number of rolls required. No openings less than 20 sq. ft. in area should be deducted, in order to compensate for cutting and fitting at such places. Add about 15 per cent, to the area to allow for waste. The border, whether wide or narrow, is usually figured as 1 roll of paper.

The cost of paper is extremely variable, ranging from 15 cents to \$6.00 per double roll; the average cost is probably 20 to 25 cents per roll for ordinary houses. Paper hanging costs from 30 to 75 cents per double roll, with strips butted, the former figure being for the usual grade of work; with lapped strips, the cost is less, being from 20 to 25 cents per roll. Sometimes an extra charge is made for papering ceilings.