Year: 1889

page_text: I WILLIAM JOHN WILSON, of 1 Chapel Road Ealing in the County of Middlesex,
Chemist 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 :-
When photographic transparencies upon clear glass are mounted for decorative
purposes it is usual to place behind the picture a piece of translucent, but not
transparent, material such as ground, or imitation ground, glass or opal glass, to form
a background for the picture, which will permit the passage of sufficient light to
render the details of the picture clearly visible whilst preventing the effect of the
picture being marred by objects situated behind the picture being visible through it.
Such photographic transparencies have also been prepared directly upon ground or
opal glass which itself furnishes both the support for the picture as well as the
necessary translucent, but non-transparent, back ground. Such ground or opal plates
have however, heretofore always been uniform over their whole surface so that the
margin (if any) beyond the edges of the picture has been perfectly plain.
The object of my invention is to provide such transparencies produced direct upon
a ground glass, opal glass, or similar support and back ground, as last referred to,
with an ornamental border or margin integral with the glass support, so that the
transparency when "printed out" or printed and developed thereon is set-off and
heightened in effect in a way not heretofore practised.
In carrying out my invention, the glass plate instead of being uniformly ground or
plain opal glass has the desired margin or border already produced upon it in any of
the ways hereafter referred to, that is to say, I use a piece of glass larger than the
picture intended to be printed thereon, a portion of the surface of this glass at least
as large as the picture being ground or otherwise rendered uniformly translucent but
non-transparent whilst the remaining portion of the surface is not uniform but is
occupied by an ornamental border or design, lettering, marginal lines, or other
variation of the surface produced by alternations of translucent and transparent glass
or of colored and uncolored portions, or of designs in relief, etc. For example, by

page_text: etching, embossing, grinding, sand-blasting, or similar process, or by the application
of a matt varnish, the surface of the glass may be rendered translucent in some places
and transparent in others. Or, a piece of flashed opal may have its opal surface
etched off in places leaving a clear marginal design or border. Again, a piece of
white glass flashed with color may have part of its colored surface etched off and then
ground for reception of the picture, the remaining portion being either left uniformly
colored or etched in a clear design upon the colored surface.
In this way, many
variations of the general idea may be made.
I coat the sheet of glass previously ornamented in any of the ways above referred
to, with a sensitive gelatine emulsion, the emulsion being applied over the whole
surface of the glass or only over that portion intended to receive the picture, and
upon this coated surface the picture is produced by printing out or by printing
and development. The picture is then fixed in the usual way by dissolving out such
portions of the sensitive salt or salts in the emulsion as have not been acted on by
light, thus leaving the picture complete, with a translucent back and an ornamental
margin or border.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is :-
The manufacture and use of gelatine emulsion coated glass plates for the production
of photographic transparencies, the said plates having an ornamental horder, design,
lettering, lines, or other variation of appearance produced in any of the ways described
upon the marginal portion of the plate before the same is coated whilst the part of
the plate to be occupied by the picture is uniformly translucent but not transparent,
as specified.
T
1500