[Table of Contents] [Search]


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: collotypes



The following is from Glaister's Encyclopedia of the book. A little long
perhaps but better than I could do in a few sentences:

By the way I have many books where 19th century and earlier plates and
playing cards have been reproduced by this method. CVery nice the detail is
quite fine and very well produced with good contrast.


collotype: a planographic, photo-mechanical, nonscreen printing process
suitable for fine detail reproductions in monochrome or colour. Printing is
done from a glass plate prepared by printing a negative on a gelatine film
containing dichromate. Fox Talbot discovered in 1852 that a chromate
gelatinc layer was case-hardened by exposure to light. The first to employ
this principle for the direct production of printing plates (lithographic
stone) was A. L. Poitevin and sheets printed by him were exhibited in Paris
in 1855. The method was given its practical adaptation mainly by Joseph
Albert of Munich during 1867—71, who introduced the glass plate. In 1869
Jakuh Husnlk of Prague issued an edition printed by Albert’s process.
Collotype came into general use under various names:
glass printing, gelatine printing, albertype, etc. In 1871 Albert had the
first collotype cylinder printing press built by Faber &Co. of Offenbach the
first satisfactory coloured collotype impression was made in 1875 and the
first three-colour collotype was made in 1898.
As now practised collotype is done in the following stages: a negative is
made of the subject with shadow masks and retouching as needed; a plate of
aluminium alloy is gelatine coated by centrifugal force to a thickness of
00005 in. and dried; it is sensitized ma bath of dichrornate and dried
again; negatives are laid on the plate and exposed by mercury vanour light;
the dichromate is washed off: finally the
is      dipped in glycerine and water, dried and mouniea, Although capable of the
finest results collotype is
slow and costly, depending on the printer’s skill more than any other
process. By 1975 only one firm in Britain was using it.
Instead of the former glass plate from which only’ 1,500 good impressions
could be taken a film base fitted to flexible aluminium plates is used on a
rota
offset machine, enabling long runs to be made. P variant of collotype is
known on the Continent
co//ograplw. With rotary machines runs of lO,O~ without appreciable loss of
quality are possible. ft America a run of 5,000 is regarded as the economic
minimum.

Regards

Kurt Klappenbach
Loud Creek Books & Bindery
P.O. Box 8120
Bangor, ME   04402-8120
207.990.3786
loudcreek@att.net

             ***********************************************
            BOOK_ARTS-L: The listserv for all the book arts.
      For subscription information, the Archive, and other related
            resources and links go to the Book_Arts-L FAQ at:
                      <http://www.philobiblon.com>
             ***********************************************


[Subject index] [Index for current month] [Table of Contents] [Search]