Improvements in the Art of Printing Pictures.
Year: 1893

page_text: COMPLETE SPECIFICATION.
Improvements in the Art of Printing Pictures.
I, CHARLES BLISS WOODWARD, a citizen of the United States of America,
residing at St. Louis, in the State of Missouri, Printer, 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 :-
My invention relates more particularly to photo-mechanical printing, by which
term I include pictures printed from cuts, engravings, etchings, lithographs or the
like made through the instrumentality of photographic processes. The invention,
however, is not necessarily limited to photo-mechanical printing, as it may be
employed with cuts or engravings made on metal, stone, wood or other surfaces,
by hand, machine, or in any other way. Its use, in connection with the latter
class of cuts would be for the purpose of imparting a degree of fineness to such
cuts, or to colouring or tinting pictures printed from such latter-mentioned cuts
or engravings. The primary object of the invention, however, is to imitate
photographs by mechanical printing, and this involves the art of photography
to a more or less extent. Pictures so made by my invention may, therefore, be
termed: "mechanical photographs" in that they are printed in a press, and
resemble photographs, and to distinguish them from photographs printed by
chemical processes, as by the rays of the sun from a negative.
In making photo-mechanical prints, a photograph is first taken of the desired
object, or a photograph of a photograph or picture of the original itself, on a
prepared surface on metal or stone, and a cut or engraving made therefrom, which
cut or engraving is placed in a press, and impressions taken from it. In a cut or
photo-engraving there must be either reticulations, cross-lines or a series of shade
lines or marks, with interruptions in or blank spaces between them, as without such
interruptions or blank spaces no distinctions of light and shade could be made, but
only solid black impressions, for instance, could be printed. The mesh of the
reticulations, or the blank spaces between or interruptions in the shade-lines or
marks, are of some considerable extent, or, in other words, the lines or marks are
some appreciable distance from one another, so that in a picture printed therefrom,
the said lines or marks are readily visible, and impart to the picture a more or
less coarse appearance, distinguishing it clearly from a photograph of the original,
consequently making it appear different from the original, and indicating that the
picture is printed from a cut. A common form of these shade marks in photo-
mechanical prints is as follows: The heavily shaded or lightly shaded surfaces
present the appearance respectively of black surfaces interspersed at uniform
intervals by white dots, and white surfaces interspersed at uniform intervals by
black dots, the intermediate shades being produced by a gradual transition from
one of these aspects to the other.
Prints made in accordance with my invention resemble photographs mainly in
one or more of the following particulars. First, the coarse or broken appearance
of ordinary prints which is due to the presence of appreciable blank spaces between
the shade lines or marks, may be remedied, and the print be made to resemble a
continuously shaded surface by printing one or more successive impressions out of
register with the first impression, the interstices between or interruptions in the
shade-lines or marks of one impression being divided, or partly or entirely filled up
by the shade-lines of the other impression or impressions. Secondly, the colour or
peculiar tint of photographs may be imitated by fixing the print by means of a
heavy impression of black ink, for instance, and also printing one or more impres-
sions of pale brown or other suitable colour, slightly out of register with the main
impression, the shade-lines or colour-lines of the brown impression, for instance,
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page_text: falling partly or wholly within the interstices between the shade-lines of said main
impression. In this manner the colours of the various impressions may be made to
blend, and by careful selection of colours, the peculiar tint of photographs (particu-
larly near the edge of heavily shaded parts of the picture) may be very closely
imitated. Thirdly, the print may be burnished or coated with a glaze to resemble
photographs.
The object of my invention is to impart to mechanically produced prints
(particularly to photo-mechanical prints), the characteristics just described. My
invention has various features applicable to other prints besides photo-mechanical
prints, but it should be noted that if the shade-lines or marks be very coarse in the
single impression, the effect of successive impressions out of register with each'
other, will often be to render the picture indistinct instead of improving it.
It is evident that if the spaces between the shading or colouring lines in the single
impression be so fine that the eye can, with some difficulty distinguish them, there
will be great difficulty in distinguishing the shading lines in a picture made
by two impressions, and a picture in which three impressions are taken will
probably have the appearance of a solidly shaded or coloured surface, that is to
say, the shade or colour-lines will blend, producing various shades, tints and colours,
the nature of which shades and colours depends on the nature of the shade or colour
lines or marks composing the various impressions.
It is not necessary that reticulations of solid lines be used. The best results will
usually be obtained by distributing the printing or shading lines or marks on the
plate in such a manner by dotted lines or in any other convenient mode, that all
or a great proportion of the shade or colour lines or marks made by the successive
impressions will fall in each case into interstices or spaces left blank by previous
impressions.
It is not absolutely essential that all the impressions composing a picture be
printed from the same plate. Evidently, for example, a picture might be fixed by a
heavy black or coloured impression from a photo-engraving of the desired object,
and the interstices between the shade or colour lines or marks might be filled in
with one or more impressions from a plate provided simply with homogeneous
shading or colouring lines or marks, and not having the image of the said object
thereon. In this manner a blending of shade or colour lines would also be achieved,
but there would be certain disadvantages in this mode of printing; for instance,
the distinctions of light and shade made in the first impression would not be
duplicated in the second impression (having simply homogeneous shade-lines or
colour-lines) and again, it would be exceedingly difficult to print two impressions
from different plates in such a manner that the shade or colour lines would be
out of register with each other to a proper and uniform extent throughout.
Another disadvantage would be the expense of providing two plates to print the
desired pictures instead of one.
In practising my invention I take the impressions preferably upon card-
board, heavy paper, or some other material of considerable body which will retain
its dimensions and shape, and which presents a finely finished surface properly
sized or calendered. I take from an engraving, a series of duplicate impressions
which I arrange to come slightly out of register with one another, so that the blank
spaces between, or interruptions in the shade-lines or marks of one impression are
divided, or partly or wholly filled out by the shade-lines or marks of the other
impression or impressions. This I may do by adjusting the cut or engraving out
of its former or first position; or by moving the card-board slightly out of
position. In practice have found that two and sometimes three duplicate
impressions out of register with each other answer to produce the effects desired.
To illustrate further, suppose, for instance, that the shade-lines of the cut or
tne cross-lines of the reticulations are one-hundredth of an inch apart. In taking
the second duplicate impression, I throw the cut or card-board one two-hundredth
part, or three two-hundredths of an inch, for example, out of its former position;
so that when the second impression is taken the shade-lines or cross-lines of such

page_text: second impression will be between the shade or cross-lines of the first impression.
This imparts a fineness of appearance to the picture which cannot be obtained by
taking one impression.
J
It will be obvious, of course, that two or more duplicate impressions may be
taken out of register with each other, and impart a still finer degree of finish to
the picture. The adjustment of the cut or card-board of course, has to be made
with the greatest precision. So far as I am aware, I am the first to take a series
of duplicate impressions thrown slightly out of register with one another, from a
photo-cut, etching, engraving, lithograph, or other cut.
I have found in practice that in taking the series of duplicate impressions
referred to, they should, to get the best effect, be with inks, colours or pigments of
different body or colour. For instance, it is necessary to take at least one impression
in heavy ink to fix the picture, but more than one impression in heavy ink of con-
siderable body and colour will blur the picture. The other impressions therefore,
should be of ink of light colour, or slight body. It matters not whether the heavy
impression to fix the picture is made first, or after the light impression or
impressions, but I have attained the best results by taking the heavy impression
first, and the light impressions afterwards in different colours. By varying the
tints and inks I am enabled to produce pictures which resemble photographs and
works of art.
My process of mechanically printing such pictures is cheaper than printing from
photographic negatives by the chemical rays of the sun, as in photography. I
am thus enabled to print, in a printing-press, pictures from engravings made from
photographs, which printed pictures may be made to resemble photographs in every
substantial respect. Such pictures have an advantage over so-called photographs,
in that they are fast and do not fade when exposed to the light, this being a serious
drawback to photographs made from sun prints.
After the picture is printed I may immerse it in a water-proof solution as a
means of preservation. I may also, after printing, pass the picture through highly-
polished heated rolls. These steps further increase the resemblance of my print
to that of photographs printed on sensitized papers and finished by the ordinary
means in the art of photography.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. The improvement in the art of printing from photo-engravings, lithographs,
cuts, etchings or other plates which print shades or colours by means of shade or
colour-lines or marks having appreciable interruptions in or spaces between them,
consisting in making successive impressions slightly out of register with each other,
the lines or marks made by each successive impression falling wholly or partly into
the interstices or spaces left blank between the shade-lines or marks of the prior
impression or impressions.
2. The improvement in the art of printing from photo-engravings, lithographs,
cuts, etchings or other plates which print shades or colours by means of shade or
colour-lines or marks having appreciable interruptions in or spaces between them,
consisting in making successive impressions in different colours and slightly out of
register with each other, the lines or marks made by each successive impression
falling wholly or partly into the interstices or spaces left blank between the shade-
lines or marks of the prior impression or impressions.
3. The improvement in the art of printing from photo-engravings, lithographs,
cuts, etchings or other plates which print shades of colours by means of shade or
colour-lines or marks having appreciable interruptions in or spaces between them,
consisting in making successive impressions in different degrees of intensity and out
of register with each other, the lines or marks made by each successive impression
falling wholly or partly into the interstices or spaces left blank between the shade-
lines or marks of the prior impression or impressions.

page_text: 4. The improvement in the art of printing, which consists in taking a heavy
'impression from a photo-engraving, lithograph, cut, etching or the like, to set or
fix the picture, and taking one or more light duplicate impressions out of register with
said first impression with ink of less body, substantially as and for the purpose
described.
5. The improvement in the art of printing, which consists in taking a series of
duplicate impressions in different colors or shades, out of register with one another,
from a photo-engraving, lithograph, cut, etching or the like, waterproofing the
picture so produced, and then polishing or burnishing the said picture to resemble
photographic prints, substantially as and for the purpose described.
Mach 1002
CHARLES BLISS WOODWARD,
Per J. G. Lorrain, M. Inst. E.E., M. Inst. M.E.,
Norfolk House, Norfolk Street, Strand, London, W.C.,
Chartered Patent Agent.