Paper is sold in sheets of different sizes and is made up into reams containing from 480 to 516 sheets; these sizes Sizes of correspond to different trade names, such for example Paper. as foolscap, post, demy, royal, &c.; the following are the ordinary sizes:—

With the enormously increased production of paper and the great reduction in price within recent years, it has been found that the “science” of paper-making has scarcely advanced with the same rapid strides as the art itself. Although a sheet of paper made to-day differsStandards
of Quality. little as a fabric from the papers of earlier epochs, the introduction of new and cheaper forms of vegetable fibres and the auxiliary methods of treating them have caused a great change in the quality, strength and lasting power of the manufactured article. The undue introduction of excessive quantities of mechanical or ground wood-pulp in the period 1870–1880 into the cheaper qualities of printing-papers, particularly in Germany, first drew attention to this matter, since it was noticed that books printed on paper in which much of this material had been used soon began to discolour and turn brown where exposed to the air or light, and after a time the paper became brittle. This important question began to be scientifically investigated in Germany about the year 1885 by the Imperial Testing Institution in Berlin. A scheme of testing papers has been formulated and officially adopted by which the chemical and physical properties of different papers are compared and brought to numerical expression. The result of these investigations has been the fixing of certain standards of quality for papers intended for different purposes. These qualities are grouped and defined under such heads as the following:—

Strength, expressed in terms of the weight or strain which the paper will support.

Elasticity and texture, measured by elongation under strain and resistance to crumpling or rubbing.

Bulk, expressed in the precise terms of specific gravity or weight per unit of volume.

Of not less importance are the qualities which belong to paper as a chemical substance or mixture, which are: (1) its actual composition; (2) the liability to change under whatever conditions of storage and use it may be subjected to. For all papers to be used for any permanent purpose these physical and chemical qualities must ultimately rank as regulating the consumption and production of papers.

In England and Wales in 1907 there were 207 mills, using 409 machines and 99 vats for hand-made paper; in Scotland, 59 mills and 111 machines; in Ireland, 7 mills and 11 machines. A rough estimate of the amount of capital embarked in the industry may be formed on the basis that average mills would represent from £20,000 to £30,000 and upwards per machine.

The table at foot of page shows the amounts and values of the British imports and exports of paper and paper-making materials in 1907.

Article.	Imports.		Exports.
	Weight.	Value.	Weight.	Value.
	Tons.	£	Tons.	£
Paper, unprinted	268,036	3,917,954	${\displaystyle \scriptstyle {\left.{\begin{matrix}\ \\\\\ \\\ \\\ \ \end{matrix}}\right\}\,}}$ 87,055	2,342,420
Paper, printed	11,494	621,293
Straw- and millboards	164,381	1,134,568
	443,911	5,673,815
Rags, linen and cotton	20,039	206,151	⁠122,909 (including other   paper making  materials.)	752,739
Esparto and other vegetable fibres	202,523	738,834
Wood-pulp—
Chemical	282,098	2,396,856
Mechanical	192,756	915,491
	697,416	4,257,332

India Paper.—This name is given to a very thin and light but tough and opaque kind of paper, sometimes used for printing books—especially Bibles—of which it is desirable to reduce the bulk and weight as far as possible without impairing their durability or diminishing their type. The name was originally given in England, about the middle of the 18th century, to a soft absorbent paper of a pale buff shade, imported from China, where it was made by hand on a paper-making frame generally similar to that used in Europe. The name probably originated in the prevailing tendency, down to the end of the 18th century, to describe as “Indian” anything which came from the Far East (cf. Indian ink). This so-called India paper was used for printing the earliest and finest impressions of engravings, hence known as “India proofs.”

The name of India paper is now chiefly associated with European (especially British) machine-made, thin, opaque printing papers used in the highest class of book-printing. In 1841 an Oxford graduate brought home from the Far East a small quantity of extremely thin paper, which was manifestly more opaque and tough, for its weight, than any paper then made in Europe. He presented it to the Oxford University Press, and in 1842 Thomas Combe, printer to the University, used it for 24 copies of the smallest Bible then in existence—Diamond 24mo. These books were scarcely a third of the usual thickness, and were regarded with great interest; one was presented to Queen Victoria, and the rest to other persons. Combe tried