Improvements in Lithographic Colour Printing, and in Preparations therefor.
Year: 1894

page_text: Date of Application, 8th Feb., 1894
Complete Specification Left, 19th Apr., 1894-Accepted, 25th May, 194
PROVISIONAL SPECIFICATION.
Improvements in Lithographic Colour Printing, and in Preparations
therefor.
We ERNEST HENRY NORBURY of the Firm of J. C. Norbury and Sons of
108 Portland Street, in the City of Manchester, County of Lancaster, Lithographic
Printers, and ALEXANDER LINDSAY GRIMSHAW in the employment of the said
firm, Artist, do hereby declare the nature of this invention to be as follows:-
Our invention relates to chromatic printing and especially to the production of
pictorial effects in more than one colour. In ordinary practice a separate stone is
required to produce each colour and also each shade of the same colour as for
example two stones are required to produce dark red and light red or pink.
The object of our invention is to simplify the process by reducing the number of
stones and as a consequence of the printing operations to the number of colours
required disregarding shades of the same colour. By means of our invention we
are enabled to produce finished effects by using only three stones for the primary.
colours in addition to a stone for the black or outline when required and of another
stone when gold is required as in ticket printing.
The darkest colours are produced by solid body colour and the lighter shades by
cross hatching or by lines or stipples. In the preparation of transfers we in the
first instance prepare the requisite number of duplicate outlines and we fill these in
to represent the several colours and shades required. At the places where the
dark body colour is to appear we fill in with black. The lighter shades are repre-
sented by gray shades. We then obtain two negatives from each of the so
prepared designs one being an ordinary negative. In the case of the other
negative a lined cross hatched or prepared glass or translucent screen is placed in
front of the sensitive plate or film the result being that the negative is cross
hatched lined or stippled according to the preparation of the screen.
We then put the two negatives together so that they register correctly and print
through both negatives upon seusitised transfer paper. The negative which has
been taken without the screen blocks out the cross hatching or stippling on the
high lights. It is necessary or advisable that one or both of the negatives shall be
on a film. We transfer the prints so obtained to the stones to be used in the
colour printing. In some cases we may use the same process in the preparation of
the stone for printing black when such is required but in other cases the said screen
would not be used in the preparation for the black printing nor in any case
wherein only one shade of a colour would be required.
Dated this 7th day of Feb 1904.
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.

page_text: COMPLETE
SPECIFICATION.
Improvements in Lithographic Colour Printing, and in Preparations
therefor.
We ERNEST HENRY NORBURY of the Firm of J. C. Norbury and Sons of
108 Portland Street, in the City of Manchester, Lithographic Printers, and
ALEXANDER LINDSAY GRIMSHAW, in the employment of the said firm, Artist,
do hereby declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement, that is to say :-
Our said invention relates to chromatic printing and more particularly to the
production of pictorial effects in several colours. In ordinary lithographic colour
printing, a separate stone is required not only to produce each colour but also each
shade of the same colour, so that suppose a picture were being printed in which a
positive colour, with say three several and additional gradations or shades of the
same colour appeared, it would be necessary to use four stones to produce the
colour and its different shades.
The object of our invention is to simplify the printing process by reducing
the number of stones, and consequently of the printing operations, to the number
of positive colours required, disregarding shades of the same colour.
By restricting ourselves to the use of the three primary colours we are enabled
to produce finished effects by the use of only three stones, each stone being devoted
to a primary colour. In addition to this it is of course necessary to use a stone for
the black or outline of the picture, and another stone when gold is required as in
ticket printing.
The darkest colours are produced by solid body colour, and the lighter shades by
lines or cross hatching or stippling.
The manner of carrying our invention into effect is as follows. The artist having
furnished a complete coloured original of the picture, we prepare the requisite
number of exactly similar outline copies, and upon each of these copies we work in,
the different gradations of shade to be developed in the picture, from the corre-
sponding primary colour, this working in being effected in black and white. For
example suppose that the primary colour were red and that the subject of the
picture were a figure in fancy costume, the deep shadows in the folds of a robe,
would be represented by the dark body colour of red, and the higher lights on the
robe by lighter shades. A still lighter shade might be used for a plume or a jewel,
or a flower, while the lightest shade of all might represent the delicate pink of the
flesh tints. All of these values would be obtained on the transfer copy by simple
gradations, from black, which would represent the body colour red, to the lightest
shade of grey, which would represent a faint pink tint in the picture.
The other two primary colours are similarly worked upon the other two transfer
copies so as to obtain the required shades, and of course the usual artifices of
arranging the printing of one colour upon another so as to obtain a different colour,
such for example as printing blue upon yellow so as to obtain a green, are employed
by us. The three primary colour transfer copies having been thus worked by the
artist, we take a photographic negative from each and in taking the negative, we
place in front of the sensitive plate, a lined, cross hatched, stippled or otherwise
suitably prepared screen of glass, the result being that the photographic negative
is lined, cross-hatched or stippled exactly in accordance with the transparent
screen.
Having obtained the requisite three negatives, we use a brush and pigment to
stop out the few high lights where it is preferable not to allow the lining, cross-
hatching or stippling to appear, and we then obtain prints from the negatives upon
sensitised transfer paper.

page_text: The transfer prints thus obtained are now put on the stones to be used in the
colour printing, and the printing may then be carried into effect.
Where extremely dark shades require accentuation beyond the darkest shade of
'body colour, we print such accentuations in black together with such black outlines
or markings as we consider requisite to sharpen the picture. These outlines and
markings are drawn upon a copy similar to those upon which the artist fixes his
values or gradations of the primary colours, and a lined or cross-hatched negative
may be taken from this black outline and marking copy just as in the case of the
colour copies, or the breaking up or hatching may be effected by hand.
But when absolutely black markings or strong unbroken outlines are required,
the cross hatching or lining of the negative and transfer is omitted, nor would such
lining or cross hatching be necessary in cases where only one shade of a colour is.
required.
:
The preparation of the outline and colour printing stones having been thus.
clearly described and ascertained, the mere process of printing from such prepared
stones need not he described. Suffice it to say that three successive printings from
the three primary colour stones gives not only the various gradations of tone in
each colour owing to the varying strength or faintness of the line, cross-hatch or
stipple marks, but also by the printing of one colour over another in their various
gradations, all of the requisite secondary colours with their shades are obtained and
the picture printed by our process is not only produced much more quickly and
easily, but has also a richness and softness of effect unattainable by the usual
process of multiple colour printing.
In the course of the foregoing description we have referred to the stopping out
of the high lights, where the lining or stippling is not to appear, on the negative,
by means of a brush and pigment. In our Provisional we proposed to effect this
stopping out of the high lights by taking two negatives from the prepared
designs, one of the negatives being taken without the lining, cross-hatching or
stippling produced by the interposition of the lined or stippled screen.
We then put these two negatives together so that they registered correctly and
printed through both negatives upon sensitised transfer paper, the negative which
had been taken without the screen blocking out the cross hatching or stippling on
the high lights.
In this process it was advisable in order to facilitate correct registering when put
together, that one or both of the negatives should be on a film.
In practising our invention however we have come to the conclusion that the
simplest mode of stopping the high lights is to stop them on the lined or stippled
negative direct and we have therefore in practice discontinued the use of the
second unlined negative as being more round-about than the direct process we have
hereinbefore described. We do not however relinquish our claim to this method
of stopping out the high lights.
Although we have referred to the use of three colour printing stones and the
three primary colours as a fitting illustration of the value of our improvement, it
should scarcely be necessary to say that we do not confine ourselves to this. In
the production of elaborate multiple coloured prints, we may of course use any
number of key tones or colours whether primary or secondary, with gradations of
such, a separate stone being used for each key tone or colour.
The advantages of our invention are however more easily grasped and understood
by referring to a typical result obtained by three printings from three primary
colours, such result not being probably attainable under the usual process by the
use of less than twice or three times as many stones and printing operations.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is.
1. The improved method or process of lithographic multiple colour printing
substantially as hereinbefore described.

page_text: 2. As means for effecting lithographic multiple colour printing, the employment.
of one lithographic stone for each primary or main colour and all of the gradations
or shades of the same colour, the transfer or printing surface on the said stone
being obtained from a photographic lined, cross-hatched or stippled negative taken
from the prepared copy referring to the said primary or main colour, and its shades
or gradations, all substantially as hereinbefore described and ascertained.
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.