Practical Bookbinding. Paul Adam
INTRODUCTORY REMARKS ON WORKING METHODS AND MATERIALS.
The bookbinder works with quite a large variety of materials which are mostly what we might call "half-made," that is to say, such materials as have already undergone some hand or machine process in order to make them fit for the work of the bookbinder. This is not the place to go into details as to the source of all these materials or the manner of their production: that may be seen in special treatises.
We separate into various groups the materials we use.
A.—Materials for Sewing and Pasting.
The bookbinder himself prepares his paste from wheaten flour and boiling water. Put in a shallow vessel, by preference a stone or enamelled metal wash-basin, the quantity of flour required for about eight days, pour in as much water as will make a mixture by soaking and stirring of the consistency of honey. Add to it boiling water, first slowly, then quicker, stirring all the time. It does not do to add the water too quickly, as that is likely to make the paste knotty or lumpy, because it cannot be stirred quickly enough and the gluten develops unequally. If added too slowly, the starch is not heated quickly enough and does not thicken sufficiently or not quickly enough, and the paste turns out too thin.
Good paste, when cold, should not be stiff like pudding, but should be easily worked with a brush. In order to prevent a skin forming on the top whilst cooling, pour over the paste as much cold water as will cover the surface immediately after the mixing with the boiling water; this water is afterwards poured off.
In summer when the paste is made, and whilst still hot, add a few drops of turpentine and mix well; this preserves the paste and keeps off insects. The addition of alum to the paste tends to make it watery, besides having no preservative properties.
If required, paste may be thinned by adding a little warm water. Potato flour is often used fraudulently for making paste, but this should only be taken when it is possible to use it up quickly, and not for books, but only for fancy goods, as this flour does not possess great adhesive power and is unsuitable for leather.
Glue is made from the well-known cake glue. The best English glue, although the dearest, is the cheapest to use. Good glue whilst soaking in water should still retain a certain degree of stickiness, must not be greasy, and should have no disagreeable smell. Glue if weighed before soaking and afterwards dried and again weighed should give no perceptible loss in weight. Good glue should not have a disagreeable taste, and above all should not betray the presence of salt.
To obtain the proper consistency in glue for bookbinding, a quantity of the cakes is taken and sufficient water poured over it to cover well. The next day the gelatinous mass is taken out of the water and dissolved in the glue-pot by placing the softened glue in a pot standing in an outer vessel containing boiling water. Glue should never be boiled nor placed directly on the fire, as that causes the loss of the best part of its adhesive property.
Glue and paste are generally worked with a brush. For paste a large hollow brush is used; this holds a large quantity of paste and covers a large surface. For glue a closer brush with a metal fastening is used, because here the hairs cannot be secured with pitch owing to the brush being constantly exposed to heat. On the paste brush there must be neither ring nor anything else of iron, as this used in paste would cause rust, and rust would give iron stains to light-coloured leathers. For the same reason no enamelled vessel should be used for paste after the enamel has once been chipped or worn.
Laying the glue or paste on a material is called glueing or pasting. A zinc-plate is the most serviceable pasting-board, as the paste is easily washed off. Glue can be scraped or soaked off and used again. Pasting-boards of mill-board or paper are hardly to be recommended, as their use entails a considerable loss of material.
Of other adhesive substances, dextrine, gum, gelatine, and isinglass are used for certain purposes. The two former are always used cold, the two latter warm. The former are dissolved in cold water; gelatine and isinglass are soaked exactly like glue, the water poured off, and then melted in the glue-pot.
Dextrine and gum are used by the bookbinder almost exclusively for pasting larger surfaces, and for laying on these substances a broad thin brush fastened with a metal strip is used.
To heat the glue and to maintain the heat a glue-heating apparatus is used. The upper part always consists of the glue-pot. The better kinds are made of copper or brass wrought or moulded in one piece. For the sake of convenience a partition is let into this pot so that thick and thin glue may be ready for use at the same time. The glue is not heated directly over the flame, but by hot water; to do this the glue-pot is placed within a larger vessel containing water, the glue-pot at the same time closely fitting to the outer rim of the larger vessel. This contrivance is placed over a petroleum, gas, or spirit lamp, which gives the required heat. In some districts where brown coal is found, it is heated on a specially made contrivance with the brown coal waste.
The latest method of heating is by electricity. The apparatus necessary for this has been put on the market by the firm W. Leo, Stuttgart.
The majority of bookbinderies, large and small, use a strong linen hemp-spun thread for sewing, the strength of which depends upon the weight and size of the sheets to be sewn. As it is inconvenient to be obliged to be continually beginning a new thread or knotting, most bookbinders use a reel of thread. The so-called Marschall thread is the best.
The book is held together by cords, for which the so-called sewing cord is used. There are now special kinds made for the purposes of the bookbinder; these are lightly twisted out of a long fibrous material so that afterwards they can be easily undone for the subsequent necessary scraping out. Certain kinds of bindings are sewn upon tapes; strong raw linen tape of 1-1-1/2 cm. being the material most generally used.
For machine sewing, thread is generally used. Tinned iron wire, ready wound on spools, is also used. It is made in various sizes and used according to the weight of the sheets.
B.—Material for Covering the Book.
The real protection against outward injury to the book lies in the cover, the inside of which consists of boards more or less strong. Of the kinds on the market the bookbinder uses grey-board, which is made from waste paper and rags. It is grey, very tough, and flexible, but dearer than other raw materials.
Straw-boards made from straw and waste paper are cheaper, but less flexible, and are easily broken. They take a very high polish under the calendering machine and become very hard, and are therefore very suitable for some work if flexibility is not essential. They are generally used in all cloth binding.
So-called leather-boards are unsuitable, for, in spite of great toughness and pliancy, they are certain to cockle and always remain spongy. Wooden-boards are unsuitable for bookbinding on account of their small resistance, but are indispensable for fancy goods and portfolios, as they can be so nicely cut and are less liable to subsequent cockling than any other kind.
Besides these, yellow and blue boards are made. These are coloured to suit and serve quite special purposes, mostly fancy goods; but they also are not used in bookbinding, on account of their high price.
The thinnest boards are known as middles. This is a strong whitish material made entirely from waste-paper. It is used for lining backs, limp bindings, and in all cases where flexibility,