Pulp and paper magazine of Canada . and issued for a further 200 or 300 analysis of these papers by volume instead of byweight, showing the actual amount of air space occupiedby the several ingredients, throws considerable light on thedifference in behaviour of the two papers. Composition by Volume. Antique. Normal. Esparto fibre Ash 0 7 Air space September 1, PULP AND PAPER MAGAZINE eoi It is clear from the above figures that the bookbinder isexpected to bind sheets containing more than double theamount of air space in the case of the antique
Pulp and paper magazine of Canada . and issued for a further 200 or 300 analysis of these papers by volume instead of byweight, showing the actual amount of air space occupiedby the several ingredients, throws considerable light on thedifference in behaviour of the two papers. Composition by Volume. Antique. Normal. Esparto fibre Ash 0 7 Air space September 1, PULP AND PAPER MAGAZINE eoi It is clear from the above figures that the bookbinder isexpected to bind sheets containing more than double theamount of air space in the case of the antique papers. The accompanying microphotographs cut from sectionsof the paper show what really takes place with papers ofthis type. Samples of the two papers were folded once and pressedlightly with the fingers. The paper was then opened upagain and a section cut at the fold. The section wasmounted and a microphotograph taken. The contrast is very marked. In the case of the normalEsparto book paper, very little disturbance of the fibres. Fig. 3.—Showing the effe af folding has taken place at the fold, the compression bringing thefibres closer together if anything. Whereas in the case ofthe antique paper, the folding of the sheet and subse-quent opening up has disturbed the fibres to an enormousextent. The amount of air space in the latter case is clearlyindicated. PAPER FOR ENVELOPESSPECIALLY CONTRIBUTED. It has been popularly supposed that because of theirshort life almost any kind of paper would do for , however, the maker of envelopes finds that the quali-ty of paper used for envelopes may vary greatly for specialuses, can be defined for specification within fairly closelimits, and the paper maker must meet these requirements. The main divisions of envelope-making are cutting, fold-ing and sticking. The points in paper-making affectingthese dividsions are:— Filler 1. Cutting Sizing FinishFillerSizing 2. Folding. Finish Half StuffMachine tendingFinish:;. Stickin
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectpaperma, bookyear1903
