Book Description

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1915 edition. Excerpt: ... A first-class grade of carbon black should always be used for blacks and lakes precipitated on very softgrained aluminum hydrate should be used for colors. An ink that separates out color or pigment to the very slightest extent should be avoided as the slightest piling on the plate makes a very bad looking job. The latitude allowed on flat-bed or rotary cylinder presses using electrotypes cannot be allowed in an ink for offset work. For tints in offset work and in fact for any colored work except black, a base consisting of equal parts of magnesium carbonate ground in a thin varnish to a stiff paste and a mixture of zinc white and aluminum hydrate also ground in varnish will be found not only a good reducer but also to give the necessary body and working qualities to the ink. SECTION TWO. DEFECTS OF INKS AND THEIR REMEDIES The usual difficulties met with in using typographic inks and their remedies are as follows: Working away from the ink rollers. Lack of distribution. Drying on the rollers. Offsetting. Flooding the type. Picking up. Fining the forms. Tinting the forms. Rubbing off after drying. Graining on the roller. Drying too fast. Not drying fast enough. Working away from the Ink Rollers in the Fountain. -- Frequently an ink will work away from the feed roller in the fountain and the result will be that the plate or forms do not get the proper amount of ink or the ink that is fed, is not evenly distributed over the form or plate and a poor print results. This is due primarily to a short ink and this condition may be caused either by the color mixing short or the use of too great an amount of short varnish. The remedy for both these conditions is to add a certain amount of varnish that has length. In cases, however, where the...