The grammar of lithography, a practical guide for the artist and printer by W D. Richmond

Author:W D. Richmond
Language: eng
Format: epub
Published: 1878-03-25T05:00:00+00:00

140. Preparation of the Stone. —The instructions usually given recommend a film of gum to be left upon the surface of the stone. This may be regarded as impossible in,practice, for the film is certain .to be thicker in some places than others, and if any mode of wiping has been used streaks will be left, over whitih the tool will partially jump, and cause an uneven line when a fine one is attempted. Fortunately it is unnecessary to leave any gum upon the surface of the stone, all that is required being to fill the pores of the surface.

The stone should have as perfect a surface as possible. This being obtained, the stone must be dried and then gummed, and dried again. The gum must not be too thin, but it will be sufficiently thick if it dries upon the stone ivith a

good gloss. If a little nitric acid be added to the gui» the subsequent coloured coating will be darker, but we think that the acid makes the stone harder to cut. If the stone has been warmed to dry the gum, it should be allowed to cool again. The stone is now to be covered with water, until all the gum has become dissolved; if the gum was previously strained, this dissolving will soon take place, but if the surface before moistening appeared rough, the hand had better be passed over to feel if any specks are left upon the stone. All the gum being now in a state of solution, the stone must be placed in a slanting position, and plenty of water poured over it to wash off the gum. It is best not to rub the stone with the hand in this operation, because all the gum that is in the stone should be kept there. When the stone is dry it will be seen whether it has been sufficiently washed, by its presenting an even appearance;. if it shines in streaks or patches it was not washed enough.

As in executing this style of work the lines are to show up light on a dark ground, it will be necessary to colour its surface. For a black ground rub in some best Paris black until the ground is as dark as it can be made. The superfluous quantity must be removed with a soft cloth, or the tracing will not adhere. A red ground may be laid with red chalky but be sure it is red chalk, as sometimes common Venetian red is substituted for it. Red chalk may be known by being smooth to the touch, and will polish when rubbed with the finger. Anything gritty or abrading must be avoided in laying grounds, and any scratches made in this operation will print The red chalk may be used dry, but it is preferable to use it in the following manner, which produces a darker and more intense ground.

Take a little powdered or scraped red chalk and a little water, rub it over

Download

Copyright Disclaimer:
This site does not store any files on its server. We only index and link to content provided by other sites. Please contact the content providers to delete copyright contents if any and email us, we'll remove relevant links or contents immediately.