Photo-engraving, Photo-etching and Photo-lithography in Line and Half-tone Also Collotype and Heliotype

Although the number increases almost every week, there are but few persons who understand photo-reproductive processes in all their details. Those who do, have been so chary of...

(_a_) _Transfer of hand-drawing._—Place the drawing to be transferred with its face upon a sheet of clean, white paper, and moisten the back with a weak solution of nitric acid...

The chemicals being prepared, they must be placed in the dark-room; the collodion bottle should be placed on a convenient shelf close to the door, and on a handy peg hang a broa...

Cut the celloidin into thin strips, or, if it be hard, break it up in a clean mortar, and dissolve in the above mixture of alcohol and ether. When dissolved, this forms the coll...

A heliotype print is made in an Albion or other type-printing press, from a film or skin of bichromated gelatine, which, having been dried upon a plate glass (finely ground and...

For etching transfers on zinc, whether photographic or direct, we shall require the following apparatus: A slab of iron about 24 × 18 inches and 1/2 or 1 inch thick, supported h...

This process, roughly described, consists in carefully grinding with fine emery, a plate of thick glass, then coating it with a mixture of white of egg, or of stale beer and sil...

Collotype plates are usually printed from, upon a typographic press, but the best press is one with a cylinder, like the lithographic machines. Such presses give a more even pre...

There is a method of making reproductions from photographs without any photographing process further than that required to supply the print. Any good photograph with a matt surf...

A suitable negative (the subject being in line, _not half tone_) having been obtained, the next stage toward producing a relief block is to make from that negative a print in in...

We have now treated of the various stages necessary to obtain a photographic transfer upon zinc, from a drawing or engraving, in line, in dot, or in stipple, first by making the...

For making grained negatives, the apparatus, chemicals, and manipulations described in Chapters I. and II., Part I., for line negatives, are required, with perhaps a little incr...

The process described in the previous chapter is most suitable for printing on zinc, for blocks that are not overburthened with fine lines, and is intended for rough printing; a...

Put the above into a wide-mouthed bottle or jar, and allow the gelatine to soak until soft; then place the vessel in a large saucepan containing cold water, and set on a fire, o...

The negative being ready for printing, select a piece of zinc a little larger each way than the picture, polish, then grain, and after well washing it under the tap and gently r...

Soak the gelatine in the water (cold) until quite soft, then melt it by the application of heat (nothing is better for this sort of work than a _Bain Marie_, a domestic utensil...

_To develop photo-litho. transfers on paper_ there are two methods. The first and oldest is, after exposure, to coat a smooth litho. stone with a thin layer of transfer ink, by...

In printing from copper plates, the ink, instead of being spread on the surface of the plate by means of a flexible roller as in ordinary type printing, is smeared over the prev...

This is a process for the production of photo-lithography in half-tone, direct from the negative, without the intervention of a collotype plate from which to pull the transfer,...

The zinc plate with the image upon it in ink, is dried, then warmed slightly on the hot plate, cooled, and coated with thick gum* and fanned dry (not dried by heat, or the gum i...

The next process under consideration is that in which the grain is given to the copper plate by dusting it with fine powder of resin (colophony) or of asphalt. To do this a dust...

This process is for making photographic reproductions of a subject in black lines on a white ground, half-tones and shadings being indicated by hatching, or stipple, but no wash...

The various methods named in the last chapter for breaking up and transferring to stone the delicate half tints of a photograph from nature, are in a great measure rather crude...

III. Light. IV. The Camera. V. About Lenses. VI. The Diaphragm, or Stop. VII. Glass-house Construction. VIII. Under the Skylight. IX. The Application of Art Principles. X. Outdo...

The former chapters have treated entirely upon the production of blocks in line—_i. e._, where the picture has been made by a draughtsman, the half-tones and gradations being co...

The improvements made within the last twenty years in the art of printing books have not, until recently, been kept pace with by the methods of illustration. Wood engraving, exc...

For all methods of heliographic printing a suitable photographic negative is absolutely necessary, and to produce that negative good apparatus and pure chemicals, used with skil...

We now come to quite a different class of work, namely, the production of half-tone intaglio plates. They may be produced in many ways, each way giving results quite unlike the...

The preceding methods of obtaining intaglio plates have been by the etching process. We now try another method whereby the printing plate is obtained by depositing a film of cop...

The ink must be good and not too thin; the rollers must be free from flaws and not too tacky. In fact, as much care is required on the press as during the photographic and subse...

This is dried in the dark, then exposed to light in a printing frame under a direct negative. It is then laid, face down, upon a polished zinc or stone, if a line subject, or on...

In all the processes and methods treated of up to Part III., the photographic negative has been what may properly be termed, a black and white negative, the lines being rendered...

This process, like photo-engraving, has been the subject of many applications to the Patent Office, but the first notable progress was made by Messrs. Bullock, in 1865. They see...