Paper and Printing Recipes Part 7

In hot, sultry weather rollers will not need sponging, as some of the materials used in their manufacture, having an affinity for moisture, will absorb enough humidity from the atmosphere to keep the surface soft.

Indeed, too much moisture is absorbed in close and sultry weather. Cover the rollers while not in use with tallow (in damp weather); this will prevent the absorbtion of moisture and keep the roller dry. When starting up put a little tallow on the distributor. This will prevent the rollers from sticking, and keep them cool.

The safest thing for the pressman is to have on hand, as a reserve, a set of old, hard rollers.

Remember, it is not dry, hot weather that causes trouble so much as it is hot moist weather. When the weather is dry, soft rollers can be used, but when dampness comes on, take out the soft and put in the old hard rollers that have become rejuvenated by the absorption of moisture.

TO KEEP GREEN MOULD FROM ROLLERS.

Nothing destroys the surface of a roller so much as green mould. It takes all the life out of them. Green mould results from a damp place and a careless pressman, and is always a disgrace to all concerned.

TREATMENT OF OLD ROLLERS.

When rollers have been lying for weeks with a coating of ink dried on to the surface--a circ.u.mstance that often occurs, more especially when colored inks have been used--get an ordinary red paving brick (an old one with the edges worn away will be the best), place the roller on a board, then dip the brick in a trough of cold water, and work it gently to and fro on the surface from end to end, taking care to apply plenty of water, dipping the brick in repeatedly; and in a short time the ink will disappear. Nor is this all; for if a little care and patience is exercised, it will put a new face to the roller, making it almost equal to new; the coating of ink having, by keeping the air from the surface, tended to preserve the roller from perishing. Sponge off clean.

A RECIPE FOR PRINTERS' ROLLERS.

Best white glue, one pound; concentrated glycerine, one pound. Soak the glue over night in just enough cold soft water to cover it. Put the softened glue in a fine cloth bag, gently press out excess of water, and melt the glue by heating it over a salt water bath. Then gradually stir in the glycerine and continue the heating, with occasional stirring, for several hours, or until as much of the water is expelled as possible.

Cast in oiled bra.s.s molds, and give the composition plenty of time to cool and harden properly before removing from the mold and inking. See that the ink is well spread before bringing the roller in contact with type.

TEMPERATURE OF THE PRESS ROOM.

The temperature of the press or machine room ought to be as near as possible the same as that at which the ink is manufactured--_viz._, 16 of Reamur (68 Fahrenheit). If the temperature of the room, and consequently, of the iron receptacles the ink is kept in, be considerably less, the varnish of the ink will stiffen, the paper will adhere to the type and peel off, or, if this does not occur, there will at least be too little varnish in the ink remaining on the type, and too much carbon, which, of course, will not sufficiently adhere to the paper, and may be wiped off even when the paint is perfectly dry. But if the temperature of the work-room be too high, the varnish becomes too thin, the ink loses its power of covering well all parts of the types, which then look as if they had been printed with lamp-oil. Colors of different hues require generally a somewhat higher temperature than black, say 70 to 75 Fahrenheit, but any printer who wants to see a clear and sharp impression of his types on the paper should not neglect to look sometimes to the thermometer, too low or too high a temperature being much oftener the cause of unsatisfactory printing than the ink we use.

WHEN TO WASH ROLLERS.

The press or machine man must be guided by the condition of the face of the roller, and the eyes and fingers will be the best guides. Where machine rollers are required for a weekly newspaper, they should be washed ready for the first set of forms, and when the number is long, a second set should be got ready and inked to work the second side, as the paper throws off a quant.i.ty of cotton waste, and powder, and neutralizes the tack so necessary to the face of a good roller and a clear impression.

Should a roller require cleaning for a hurried work, the old ink may be removed with turpentine, but must be done quickly, and immediately distributed on the ink table, or the face will harden.

IMPROVED DRYER FOR PRINTING INK.

A small quant.i.ty of perfectly dry acetate of lead or borate of manganese in impalpable powder will hasten the drying of the ink. It is essential that it be thoroughly incorporated with the ink by trituration in a mortar.

HOW TO BEND A RULE.

To bend a rule, get it thoroughly hot and let it cool slowly; this will take the spring out, and it will stay in the shape it is bent to.

TO CLEAN GILT FRAMES.

Use a soft sponge moderately moistened with spirits of wine; allow to dry by evaporation. Do not use a cloth, and avoid friction. Another way is to use a very soft shaving brush, and to gently rub backward and forward a lather of curd soap. Rinse with water at about blood heat. This applied morning after morning to old and dirt-covered oil paintings will greatly restore them. In adopting this plan with regard to gilt frames around water colors or prints, be sure that not enough moisture is used to run off the frame, or the paper will be stained. The cleaning applies to gold frames only. Dutch metal will bear no cleaning, but a new material, not absolutely gold, but very like it, will stand any amount of soap and water.

CLEANING NEW MACHINERY.

As presses and machinery have their bright work covered with a compound to keep it from rusting while shipping, parties who receive the machinery will find benzine or kerosene oil the best articles to clean off the compound with.

TO MAKE INVISIBLE WRITING.

To make secret or invisible writing, procure some very thin starch, with which write with a quill pen (which should be a soft one) anything that fancy may dictate. Suffer it to dry perfectly; examine the paper upon which you have written, and not one letter can be distinguished by the naked eye. Procure a little iodine, which is an elementary body, dissolve it in water, and with a camel's hair pencil, a quill, or any other convenient article, dipped in the solution, slightly rub the paper on the side which has been written upon; the writing will instantly appear as distinctly visible as if written with the finest ink ever invented.

RED PRINTING INK.

Red printing ink may be made in this way:--Boil linseed oil until smoke is given off. Set the oil then on fire, and allow it to burn until it can be drawn out into strings half an inch long. Add one pound of resin for each quart of oil, and one-half pound of dry, brown soap cut into slices. The soap must be put in cautiously, as the water in the soap causes a violent commotion. Lastly, the oil is ground with a sufficient pigment on a stone by means of a muller. Vermilion, red lead, carmine, Indian red, Venetian red, and the lakes are all suitable for printing inks.

TO PREVENT ELECTROTYPE BLOCKS FROM WARPING.

To prevent electrotype blocks from warping, shrinking or swelling, place them in a shallow pan or dish, cover with kerosene oil and let them soak as long as possible, say three or four days. Then wipe dry and place in the form. After the first two or three washings they may swell a little; if so, have them carefully dressed down, and after that you will have little or no trouble with them, and can leave them in the form just as you would were they solid.

BLACK PRINTING INK.

To make a good, permanent black printing ink, take

Balsam copaiva 9 oz.

Best lampblack 3 oz.

Prussian blue 1-1/2 oz.

Indian red 0-3/4 oz.

Turpentine soap, dried 3 oz.

Grind on a stone until extreme fineness has been obtained. This ink will work clear and sharp, and can easily be removed from the type.

SEALING WAX.

Following are formulas for making sealing wax:--Fine red sealing wax--Pale sh.e.l.lac, 4 oz.; Venice turpentine, 10 drachms; English vermilion, 2 oz.

Ordinary red sealing wax--Sh.e.l.lac, 2 oz.; resin, 4 oz.; Venice turpentine, 12 drachms; chrome red, 12 drachms. Cheap red bottle wax--Resin, 10 oz.; turpentine, 1 oz.; beeswax, 1-1/2 oz.; tallow, 1 oz.; red lead or red ochre, 3 oz. The manipulation is about the same for the three kinds. First, the resins are melted with as low a heat as will suffice, then the turpentine, previously warmed, is to be added, and lastly the coloring material. The first quality is only used in sticks, and the third, when melted, for dipping bottles in. The second can be employed for either purpose. When the wax is used for dipping it should be kept at a temperature just sufficient to render it liquid, as too much heat causes it to foam and to rapidly become brittle. Even with this precaution, it is necessary to add a little turpentine, from time to time, to replace the essential oil lost by evaporation.

FOR MAKING DEXTRINE.

Five hundred parts of potato starch are mixed with 1,500 parts of cold distilled water and eight parts of pure oxalic acid. This mixture is placed in a suitable vessel on a water-bath, and heated until a small sample tested with iodine solution does not produce the reaction of starch. When this is found to be the case the vessel is immediately removed from the water-bath, and the liquid neutralized with pure carbonate of lime. After having been left standing for two days, the liquor is filtered, and the clear filtrate evaporated upon a water-bath until the ma.s.s has become quite a paste, which is removed by a spatula, and having been made into thin cakes is placed upon paper and further dried in a warm situation; 220 parts of pure dextrine are thus obtained.

When needed for making mucilage, the solution has only to be evaporated to the proper thickness.

COLORS FOR PRINTING INKS.

The different colors, and the inks which may be made from them, are as follows: