aphic P

ions-Offsets-The Lithographic Hand-roller-Proving-Registration-General Features-Transferring

press actually employed for printing purposes. Its ready adaptability to the ever-varying thickness of lithographic stones, and the manner in which pressure can be applied at will, as well as the intense sharpness of such pressure, render it peculiarly suitable for the work now under discussion. Such operations will be better understood and probably more easily remem

quire a stronger ink for its successful treatment. Between these two extremes there is a variety of conditions and effects which will require a ready recognition and an intelligent adaptation or modification of any operation which may be described. It may even be advisable to rub up the work with a piece of soft rag and printing ink, but the clearness and crispness of the drawing can best be preserved by a complete removal of the greasy ink with which the drawing was originally made. More particularly is this desirable when heavy, solid work is in close contact with work of a finer description, for the excessively gr

and acid, after which the gum solution is allowed to dry. The chemical change which takes place during this etching is often described as one in which the soap present in lithographic chalks is changed to an insoluble compound. This chemical change is p

d of washing out the drawing with turpentine immediately, work off the original chalk by rolling up with a good nap roller and taking frequent impressions. In t

btle suggestiveness which gradations of tone can impart to a chalk drawing before he can hope to successfully reproduce the artist's original conception. A good printer handles his roller over a chalk d

airly strong nitric acid. Polish slightly, and wash well with a plentiful supply of clean water. Pour over the stone a very weak solution of alum, and again wash thoroughly with hot water, so that its rapid evaporation may leave the work ready for immediate manipulation. Alterations

Being an alkali, a strong solution would have a tendency to dissolve th

subsequent manipulation. These impressions will not only reveal any inaccuracies or weaknesses which might otherwise pass

they frequently constitute an intermediary stage between the first drawing of the draughtsman on stone and t

or outline forme. Dust these over with a mixture of three parts Venetian red and one part lamp-black. Lay them in convenient positions on a well-polished dry stone, and run them through the lithographic press with a light yet firm pressure. The result will be faint yet sufficiently clear offsets of an outline which

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French calf-skin with a soft, velvet-like nap, and may be prepared as follows. Run the roller in crude castor oil for a short time until the leather becomes soft and pliable, then work out the superfluous oil by repeated rolling in medium varnish, occasionally scraping off the varnish with a broad blunt knife. Continue this for a day or two, then gradually work into the skin some goo

he realisation of their colour schemes, and to amplify or minimise if necessary the effects they desire to produce. Errors of judgment or of detail can be rectified before the work reaches a more advanced st

ecedes it, and the arrangement for machine printing which follows. The distinctive and pre-eminently the most important feature of proving is the manner in which one colour is registered with another; and although the methods usually adopted are of the simplest possible character, the most scrupulous care is requisite for their successful application. It appears to be an almost ridiculous plan, so simple

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he only probable complications which may have to be considered. Then again, many phases of the work are more or less experimental, when the resourcefulness of the printer may be tested, and the mechanical features of his work be relieved by the exercise of intelligent application, if not of artistic perception. Very rarely is it possible to print from the litho-draughtsman's original drawing, and even when it may be convenient to do

hich the duplicating of original work by means of transfers was first evolved, it is only reasonable to suppose that it was the direct outcome of a necessity which was as peremptory in its demands as it has been far-reaching in its effects. The method is one by which any number of impressions can be made on a suitably prepared paper, and with a sufficiently greasy pigment. These can be re-tra

he size of the work is 7? in. by 4? in., then the paper on which it is to be printed ought to be double crown, 20 in. by 30 in. This will allow 1? in. for the gripper and ? in. margin at the back and sides. Sixteen transfers can be pulled from each colour forme o

used the stone must be slightly damped. If the sheet of transfers is laid down to a board-Fig. 12-uniformit

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pon which they were arranged, as it is usual to secure them in position with paste. At this point the manipulation of the two varieties of paper differs slightly. The thin, transparent variety is usually fastened down to its paper base with syrup, glucose, or some sticky composition of a similar character. This

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the latter being thinned down with turpentine and varnish. Gum up the work, and allow the gum to dry. Roll a piece of soft rag into a pad, and charge it with printing ink which has been thinned down. Wipe off the gum on the surface of the stone, leavi

ond and third sets of transfers being patched

ly place each transfer in its exact position. They can then be laid down on separate stones in the same way as the first set. These are the simple outlines of the transferring process. In det