_Note._--The mean breaking strain and mean stretch required are given for each paper. The figures represent the mean of the results obtained for both directions of the sheet, and are calculated on a strip of paper two inches wide and having a free length of seven inches between the clips. In the case of papers indicating a larger breaking strain than the minimum required, a proportional increase in the stretch must also be shown. _Class 10. Brown Paper, Cylinder-dried._ _General Specification._--Machine-made. _Note._--The mean breaking strain required is given for each paper. The figures represent the mean of the results obtained for both directions of the sheet, and are calculated on a strip of paper two inches wide and having a free length of seven inches between the clips. _Class 11. Smallhands._ _General Specification._--Machine-made. Engine-sized. _Class 12. Buff Papers._ _Specification._--Highly finished both sides. Machine-made. Hard engine-sized. Mechanical wood pulp must not be used in the manufacture of any papers, with the exception of engine-sized coloured printings, and buff papers, where an addition up to 25 per cent. will be allowed. All animal tub-sized papers are required to be as far as possible free from earthy matter; and, except where specially stated, the amount of _loading_ added to other papers must not exceed 6 per cent. When sulphite or soda pulps are used, either separately or conjointly, in the manufacture of printing papers, the quantity of neither material shall separately exceed 50 per cent. The most complete specification as to the requirements for standard papers is that published by the Paper Testing Institute in Germany, and used as the basis of most contracts, at least for public and official documents. _Standards of Quality in Germany._--The classification of papers according to the raw materials used and the nature of the finished paper is very complete. The classification is made under three headings: (_A_) Raw Material; (_B_) Strength; (_C_) Uses. _(A) Classification according to Material._ (1) Paper made from rags only (linen, hemp, and cotton). (2) Paper made from rags with a maximum of 25 per cent. of cellulose from wood, straw, esparto, manila, etc., but free from mechanical wood pulp. (3) Paper made from any fibrous material, but free from mechanical wood pulp. (4) Paper of any fibrous material. _(B) Classification according to Strength._