|
|
Early
Photographic Processes
Photogravure
1879
-
|
|
Discovery |
Photogravure is
a photomechanical process. Printing plates are etched from
photographic images. This process can produce high quality prints in large quantities.
The process is derived from Talbot's photoglyphic engraving.
In
1879, Karl Klic (Klietsch) (1841-1926)
modified the process by using copper cylinders instead of plates.
This was known as
rotary printing or rotogravure. However, Klic kept this process to
himself, and it was not until 1910 that rotogravure started to be used in
newspaper printing. |
|
Process |
Photogravure consists of etching an image
on a copper plate, previously-prepared with a grained surface, so that
the etched area can hold printing ink.
Description of the process
1. Prepare a copper
plate by cleaning with a weak acid then with potash.
2.
Lay a ground upon the copper plate.
The ground is made by
up of fine dust and bitumen. Warm the plate gently until the
bitumen adheres to it.
3.
Use the original negative to make a carbon positive on a transparency,
and allow to dry.
4.
From the carbon transparency make a carbon negative onto, say, Autotype
tissue.
This is called a resist
because it will, at a later stage, resist the action of the etching
fluid.
5.
Lay the resist on the grained copper plate and develop (as for a
carbon print) with warm water. Then dry the resist, using alcohol
to do so.
This will
leave a coating of gelatin on the ground copper surface, thinnest in the
shadow.
6.
Etch the copper plate through the resist.
Do this by
placing in a dish containing perchloride of iron.
7.
Wash the resist off the copper plate, then print from the
plate.
The printing is
normally performed by a professional copper plate printer. |
|
I believe that the notes above were
taken from a book published in the late 19th century. Below is a
rather different description based on an account in Looking at
Photographs by Gordon Baldwin
Alternative description of the process
Proceed as above, except replace steps
3, 4, 5, 6 by:
3a. Use a negative of the picture
to be reproduced to create a transparent positive
4a. Coat a tissue on one side with
gelatin sensitised with potassium dichromate, then expose it to light
under the transparent positive.
The gelatin will harden more on those parts
receiving the greatest amount of light.
5a. When wet, firmly press this
tissue, gelatin side down, onto the prepared copper plate, then peel away
the backing in warm water.
6a. Place the plate in an acid
bath, where the parts with the least covering of gelatin will be etched
more deeply. |
|
1893 Lecture
The
process above was described at a lecture given to the Photographic
Society of Great Britain in 1893.
The
journal Photography, commenting on the lecturer, Mr
Dennison, reported:
"...
the Society, and photographers generally, have been in luck's way to
secure so capital an exposition and so lucid a lecturer upon an almost
unknown process."
[Photography:
2 Mar 1893] |
|
Result |
The photogravure process is generally
highly regarded, being able to produce high quality copies, with the
images with
charcoal blacks and bright whites,
embedded in the fibres of the paper.
Results using rich sepia
ink can also be very attractive.
Photogravure images have
been described as having the subtlety of a photograph and the art
quality of a lithograph.
[Appalachian
Arts web site]
The finished picture shows
the mark of the plate around the picture. The process can produce |
|
In
Edinburgh
|
James Craig Annan
visited the Austrian printer Karel Klik. In three weeks, Annan was
taught the photogravure process, and for a cost of 2,500 Austrian
Florins was granted permission to use the process in Scotland. He
was not allowed to disclose details to others, the penalty for doing so
being 10,000 Austrian Florins. [Bill
Buchanan]
In the early 1890s, he made photogravure
prints from some of Hill &
Adamson's calotype negatives, and to used them to promote Hill &
Adamson's work internationally by sending the photogravures to
exhibitions.
James Craig Annan made a fine set of photogravures of
his father's images of the
Old
Closes and Streets of Glasgow. T&R Annan published these in 1900. |
In 1892, when the Photographic Federation of the United
Kingdom came to Edinburgh for their annual excursion and series of
meetings, Edinburgh was well covered by reports in the photographic
journals.
The British Journal of Photography reported on a visit
to James Good Tunny's studio, mentioning that in addition to processing
his own work, JG Tunny also handled photogravure work for the trade.
Thirty years later, photogravure still appears to have
been topical. Victor L Alexander gave a lecture to
Edinburgh Photographic Society on the photogravure process on 5 April
1922. |
|
