Transparencies.
Year: 1886

page_text: Transparencies.
We WILLIAM JONES of 2° Rye Dwellings, Peckham Rye, in the County of
Surrey, Map Mounter, and RICHARD CHARLES POWELL of 8 Victoria Buildings,
Belgravia, S.W. Gentleman, 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 :-
This invention relates to the preparation of transparencies from pictures,
photographs, prints, designs, or the like previously printed or drawn on paper
and the object thereof is to provide a suitable "sheet" differing from the paper
ordinarily used in that it possesses sufficient strength to bear the weight of colour
and for the purpose of "securing the register" and yet may be readily detached
or attenuated to the required degree of transparency. The term "securing the
register" will be well understood by those skilled in the art; it has reference to
the coinciding of the colours on the stones with the proper places upon the sheet
upon which they are to be printed.
"
"
In carrying out our invention we use a "sheet" composed of " 'tracing-tissue'
news"-paper cloth or other suitable substance and coat it on both sides with a
varnish composed of the following ingredients, viz:—
•
Two parts by measurement of white spirit varnish.
Two parts methylated spirits.
One part turpentine.
One part castor oil; the whole to be thinned down by paraffine or other
mineral oil and by preference scented with verbena or other essential oil. The
paper or cloth having its surfaces coated with the above varnish is then pressed and
covered on one side with spirit varnish and backed on the other with one or more
layers of cartridge drawing, printing or lithographic paper or other suitable
strengthening material attached by means of starch or other adhesive material and
again pressed. The surface of the "tracing-tissue or "news"-paper or textile
fabric is then covered or faced with an "enamel" consisting of gelatine-glue and
glycerine; the enamel known as Cory's mountain-snow or other enamel and
again rolled or pressed and allowed to dry when the enamelled surface is ready to
receive the picture design or print which may be applied in the usual manner.
"
"
"

page_text: "
The "sheet we employ thus consists of an enamel face applied to a "body" of
"tissue" of fine quality supported by a stronger backing.
"
To produce a transparency the printed or ornamented face of the "sheet" and
the glass are coated with varnish and when dry the sheet is attached to glass by
a mixture of gum and alum or other adhesive material being well pressed thereon
and all air-bubbles being removed by means of
"in the manner
squeegee
a
usually practiced by those skilled in the art of mounting prints or drawings.
After the adhesive material has had time to dry a process which usually requires
about a day the backing is moistened with glycerine and water and if proper care
be taken the backing and also the "tracing-tissue" or body can be removed sheet.
by sheet until nothing remains upon the glass but the enamelled face bearing the
color or impression and the varnish with which the picture and glass are coated.
When the desired degree of attenuation or transparency has been arrived at the
transferred picture may be either coated on the back by a protective varnish or it
may be French polished or protected by glass.
When it is required to apply the print or design to non-transparent surfaces such
as china or opaque glass it is fixed thereon by means of a volatile or combustible
varnish the body and backing are then removed as above described, leaving the
film of color and enamel and the china or glass is then fired in the usual manner.
We do not confine ourselves to the precise proportions of the ingredients which
we have herein mentioned although we find these to give satisfactory results.
'
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
"
1. For the production of transparencies the use of the "sheet" consisting of an
enamel face to receive the print or design a "body" of "tracing-tissue or other
equivalent material and a backing of stronger material substantially as specified.
2. The process of making the said "sheet" consisting in varnishing the "body'
pressing and enamelling the same and backing it with stout paper or other
strengthening material substantially as specified.
"
3. In the production of transparencies the combination with the " body" of
tracing tissue or equivalent material of an enamel face substantially as specified.
4. Strengthening the "tracing tissue" or "body" of the "sheet" intended to
receive the picture print or other design by backing it with one or more layers of
paper or equivalent strengthening material to enable it to carry the weight of color
and for the purpose of ".securing the register" substantially as specified.
5. The process of applying pictures to china or glass by the use of the herein
described "sheet" attached by means of a volatile or combustible varnish and
afterwards firing the articles substantially as specified.
Dated this 3rd day of July 1886