Bertrams' Single-sheet Cutter.—In cases where it is necessary that the sheets should be cut with great uniformity, as in the case of paper bearing a water-mark, in which it is requisite that the design should appear exactly in the centre of the sheet, the ordinary cutter is not found to be sufficiently reliable; a machine termed a "single-sheet cutter" is therefore used for this purpose, of which an illustration is shown in Fig. 42. The paper is led direct from the paper-machine, or from a reel frame, to the drawing-in rolls, A; after which it passes through the circular slitting-knives, B; from here it is led by the roller C to a large wood-covered drum, D, and at the front of this drum the sheets are cut by the cross-cutting knives, E. There are two cast-iron tapered cones, with belt guide for adjusting the speed; a fly-wheel to promote steadiness in working; a series of wrought-iron levers, cranks, eccentrics, shafts, etc., for accurately regulating the travel of paper and the cut of the horizontal knives; a small pasting table is also fitted across the machine for mending broken sheets.
Packing the Finished Paper.—The paper, after it leaves the cutting-machine, is conveyed to the finishing-house, where it is carefully examined by women, who cast aside all defective or damaged sheets, which, under the trade names of "imperfections" or "retree," are sometimes disposed of, at a lower rate, to the customer for whom the order is executed. In the warehouse these imperfections are marked with a capital R on the wrapper, or two crosses, thus X X. If the paper is broken, it is sometimes marked B X X; it is not generally the custom, however, to sell imperfections, but to return them to the beater-man, to be re-converted into pulp. The perfect sheets are then counted, and packed up in reams consisting of 480 to 516 sheets.
Sizes of Paper.—The various sizes of paper are known in the stationery trade under different designations, as demy, crown, double crown, royal, imperial, etc. As paper is generally purchased according to weight, the various weights per ream are also distinguished with the size of the paper, as 16 lb. demy, 22 lb. double crown, and so on. The following table shows the sizes of some of the writing and printing papers in common use:—
| Name. | Writing Papers. | Printing Papers. |
| Inches. | Inches. | |
| Foolscap | 17 × 13¼ | 17 × 13¼ |
| Small post (or post) | 18¾ × 15¼ | 18¾ × 15¼ |
| Crown | 20 × 15 | |
| Double crown | 30 × 20 | |
| Demy | 22½ × 17¾ | |
| Royal | 25 × 20 | |
| Imperial | 30 × 22 | |
| Double demy | 35½ × 22½ | |
| Double royal | 40 × 25 | |
[CHAPTER XV.]
COLOURED PAPERS.
Coloured Papers.—Colouring Matters used in Paper-Making.—American Combinations for Colouring.—Mixing Colouring Materials with Pulp.—Colouring Paper for Artificial Flowers.—Stains for Glazed Papers.—Stains for Morocco Papers.—Stains for Satin Papers.
Coloured Papers.—There are several methods by which any desired shade of colour may be imparted to paper, which are as follows:—