[Illustration]
COLLOTYPE
AND
PHOTO-LITHOGRAPHY
PRACTICALLY ELABORATED BY
DR. JULIUS SCHNAUSS,
Member of the Imperial German Academy of Naturalists, &c.
TRANSLATED, WITH THE AUTHOR’S SANCTION AND ASSISTANCE,
BY
EDWIN C. MIDDLETON.
TOGETHER WITH AN APPENDIX ON
STEAM PRESSES,
BY THE TRANSLATOR.
LONDON:
ILIFFE AND SON, 3, ST. BRIDE STREET, LUDGATE CIRCUS,
1889.
PRINTED BY ILIFFE AND SON, 3, ST. BRIDE STREET, LUDGATE CIRCUS,
LONDON, E.C. WORKS: COVENTRY.
CONTENTS.
CHAPTER. PAGE.
I. Introductory 9
II. Bichromates in Conjunction with Organic
Substances 12
III. Summary of the more important Printing
Processes with Chromated Gelatine 18
IV. Collotype Apparatus 25
V. Chemicals and Materials for Collotype 46
VI. Preparation of the Collotype Plate 59
VII. Negatives suitable for Collotype 72
VIII. Printing in the Press 88
IX. Finishing and Varnishing Collotype Prints 96
X. Other Collotype Processes 102
XI. Failures in Collotype: In the Preparation of
the Plates 107
XII. Investigations on Collotype 114
XIII. Collotype in Natural Colours 119
XIV. Magic Prints 122
XV. Photo “Glass” Printing 124
XVI. Allgeyer’s Collotype Process 127
XVII. Practice of Photo-Lithography 130
XVIII. Autography 135
XIX. Negatives for Photo-Lithography 149
XX. Application of the Carbon Process to
Photo-Lithography 155
APPENDIX.
Steam Presses 162
TRANSLATOR’S PREFACE.
The impossibility of obtaining any work in the English language on
the subject of Collotype first led to my translation of the German
work of Dr. Schnauss, and the fact that no work has hitherto appeared
fully dealing with the matter is the excuse I offer for the present
publication. The translation is necessarily one of considerable
freedom, but it is offered as containing all the information to be
found in the original, and in addition, considerable extensions, made
with the author’s consent. The omission of the chapter dealing at
length with the steam machine was necessitated by the fact that the
rotary machine there described is no longer manufactured.
Without pointing to the frontispiece in any sense as a high-class work,
it may serve to show that I have made some practical acquaintance with
the subject. The illustration, printed on ordinary paper, was produced
from the instructions found in this work, and I may add that at the
time of writing I have printed over 500 impressions from the first
plate, and it still remains in fair working condition.
EDWIN C. MIDDLETON.
STANMORE ROAD,
BIRMINGHAM.
COLLOTYPE AND PHOTO-LITHOGRAPHY.
CHAPTER I.
INTRODUCTORY.
The observation by Mungo Ponton of the sensitiveness to light of
bichromate of potassium in conjunction with organic substances is but
little more recent than the discovery of photography itself. If sized
paper is saturated with an aqueous solution of this salt and then
exposed under any transparent design, the latter will be reproduced
as a negative of a brown colour on a yellow ground. If the exposed
paper is placed in water, the bichromate salt will be removed from
the unexposed, and consequently unaltered portions; the image will
remain brown after this treatment, though somewhat bleached. The
sensitiveness to light is proportionately increased by the addition of
larger quantities of organic substances, as starch, paste, glue, sugar
or gum, as first observed by Becquerel. This arises in consequence of
the organic matter being oxidised by the chromic acid, a corresponding
decomposition and reduction of the chromate salt to chromate of
chromium taking place.
In the year 1853 an Englishman—Fox-Talbot, the gifted discoverer of
calotype (_i.e._, the production of photographic negatives on paper
by means of silver salts)—followed up the lines of these important
observations, and discovered that the mixture of bichromate of
potassium and glue entirely lost its solubility and power of swelling
in cold water after exposure to light, and on this he based his process
(heliography) of etching on metal plates. The plate, after receiving a
coating of the chromated gelatine solution, was dried, exposed under
a positive, and afterwards developed or washed out in warm water, all
unexposed and consequently soluble portions being removed, while the
exposed and therefore insoluble portions covered as a negative[A]
the metal plate, and so protected it in those parts from the etching
mordant employed, usually chloride of potassium or perchloride of
iron. His successor in these researches was a Frenchman, Poitevin, who
invested these processes with even greater practical importance. He,
however, worked chiefly on paper with the bichromate mixed with albumen
or gelatine, and attained results which were the first practical steps
towards photo-lithography and carbon or pigment printing. Further on
we shall return with more detail to these subjects. In the hands of
Tessié du Motay and Marechal, of Metz, the discoveries of Poitevin
derived further practical value, and to them we are indebted for the
first advances in collotype, they in their practice using metal plates
as a support. Joseph Albert, of Munich, followed, and introduced
further and considerable modifications, amongst others utilising glass
plates as a foundation. The want of adhesiveness of the chromated
gelatine layer to its support was a source of great trouble to the
earlier experimentalists, and was a matter giving rise to innumerable
difficulties, which were, however, finally surmounted by the researches
of Husnik, Albert, and Obernetter.
[A] For the production of an intaglio plate the impression on the
chromated gelatine must be printed from a positive, which will
naturally give a negative on the copper plate.