Practical Bookbinding. Paul Adam

this levelling work, the pasted part will still be noticeable; the thoroughly dried sections are therefore taken in batches of four or five, knocked up at the back edge, and the thick part carefully hammered on a stone or iron bed.

      Just as paper strips have been used in this work, linen can be used for guarding atlases and mounting large maps which are intended for long and constant use. To fill out the back, cardboard or thick drawing-paper the thickness of the plates (or, if anything, a little less) is used. Of this material strips are cut 1 cm. in width and same length as the height of the work, cutting a strip for each plate of course. Besides these strips, cut some soft white calico into strips 3 cm. in width. These are pasted, laid quite straight upon a clean board, two strips of paper are placed in the centre side by side on top of the pasted strip, and at right and left of each a map is hinged on, the first face downwards, the second face upwards. When dry, the section so made is creased in the middle, knocked down with the hammer, and pressed for a time. By this method two plates are hinged on each guard; by the other each plate had its own guard.

      Many books are issued with plates larger than the format of the book itself; they must be brought to the right size by folding, but in such a way that the folded plate is secure from injury during any subsequent trimming.

      Before making a single fold in the plate, the worker should clearly see his way through his scheme for folding, so as to bring the plate to the size required with the smallest possible number of creases. Plates which are slightly wider and longer than the size of the book are easily made to fit if they are folded once or, if necessary, twice across the middle, pasting the edge of one fold on a guard and then fixing in its place in the book.

      

Figs. 9-13—Suggestions for folding plates and maps.

      If this will not do, the plate must first be folded up from the bottom edge far enough to escape damage in trimming, and then the long side must be similarly folded. Larger plates must take more folds, always working on the principle that the length of the book should first be obtained in the best possible way, and afterwards the width is taken as the guide in making the folds.

      In doing this the plate must be folded now to the front, then to the back, so that on drawing it out it opens in a zigzag fashion. For the sake of clearness we give illustrations showing the most general methods of folding. The part marked A is secured in its place in the book by mounting on a paper guard; but one may, by cutting out the map properly, leave a small margin which will serve as a guard as shown in Figs. 10, 12, and 13.

      In all cases, however, it is essential that the thickness of the folded plates should be equalised by inserting guards in the back of the book.

      Formerly, when several plates were inserted one after the other, it was customary to place them in such a way that they were trimmed at top and bottom alternately; now they are placed so that they are all trimmed at the top edge: this is much better, because it keeps the top edge smooth and close, thereby keeping out dust and insects. The accompanying sketches are based upon this principle.

      The so-called two-page illustrations in periodicals must be treated in the same way. These are only possible in the middle of a section, where they would be caught into the back and injured if the following precaution were not observed. Such illustrations are taken out, the back edge pasted, and then placed in the back so as to adhere to the following sheets, projecting about 1/2 cm.

      The printed sheets thus treated must now be collected by the same process—that is if they have not been gathered in open sheets in the printery—into volumes; this work is generally known as gathering after folding.

      As in gathering open sheets, the piles of folded sheets are placed side by side; but as these take up so much less room than the open sheets, in most cases the whole work may be laid out at one time.

      Clear the longest table procurable, which if not long enough must be extended by the addition of small tables, trestles, &c., upon which are laid the batches of sheets in fifties, and, beginning with the last sheet, work up the row until the title page is reached and the gathering ended. Starting from the left, the gathered sheets are placed to the right; after the last sheet, i.e., the title page, there should be sufficient room for placing the gathered sheets and also, if possible, for knocking up and collating, that is, checking the sequence of the sheets. The gatherer begins with the last sheet on the left, draws the top sheet with the right hand on to the left hand held flat to receive it, and so goes along the row, drawing from each pile one sheet, which drops into its place on top of the preceding one in the left hand. This work can be carried on simultaneously by several persons following each other, but there must be a sufficient number of persons stationed at the end ready to knock up and collate the gathered sheets. In order to simplify this work and to enable one to take up the completed gathering at the title page, the pile containing the title page sheet is plainly marked across the back with a blue or red pencil, so that one sees on the back of each single sheet a coloured mark easily seen in the gathered and knocked-up sheets.