AN IMPROVED MODE OF PRODUCING ORNAMENTAL SLABS AND PANELS
Year: 1880

page_text: LETTERS PATENT to Alexander MoLean and George Green, both of Bankside,
in the Borough of Southwark, for the Invention of "AN IMPROVED MODE OF
PRODUCING ORNAMENTAL SLABS AND PANELS."
PROVISIONAL SPECIFICATION left by the said Alexander McLean and
George Green at the Office of the Commissioners of Patents on the 18th
February 1880. ..
ALEXANDER MCLEAN and GEORGE GREEN, both of Bankside, in the Borough of
Southwark. "AN IMPROVED MODE OF PRODUCING ORNAMENTAL SLABS AND
PANELS."
The object of our Invention is to produce ornamental slabs in various colors,
and with any variety of pattern, to be used for mural or other internal decoration
in a cheap and easy manner.
In carrying out our Invention we prepare a slab of plaster of Paris of the size
of the ornamental slab required, and having obtained a perfectly smooth surface we
transfer onto it a design or picture in outline in any convenient manner, and
incise the lines with a graver or other tool, and thereby form a mould. From this
mould we take a cast in cement (preferably Keen's), or it may be paper pulp or
other suitable material.
When this cast is removed from the mould it will constitute a plate with the
outlines of the design or picture in relief.
This cast is now to be used as a mould, from which any number of slabs for
mural or other decoration may be made, and preparatory to its use it should be
coated with shellac or other varnish.
In employing this mould we fill the spaces circumscribed by the design with
cement, in a plastic state, of any desired color; we next cover the whole slab with
cement of another color, to any desired thickness, to form not only the ground
work of the picture but the back of the slab intended to be made.
As soon as the cement is quite hard we remove the slab from the mould and
place it upon a flat table. The slab is then carefully examined, and any air holes
are filled up and blemishes made good, and it is carefully rubbed down with stone
until it has a perfectly smooth and even surface.

page_text: We have now obtained an ornamented slab in which the body of the picture or
design and the ground work are filled in, but without an outline as this remains
in intaglio.
.
To fill in the outline we use by preference a dark colored cement which while
in a plastic state we smear over the picture or design, taking care that all the
lines shall be properly filled in. We then remove the superfluous cement with
a straight edge or a sponge, and the picture is completed.
The slab may then be polished in any convenient manner, and will when inserted
in place form a very effective style of decoration.
It will be obvious that the number and shades of the colors used may vary
according to taste.
In place of cement paper pulp may be used, the process of producing the design
or picture being the same.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander MoLean and George Green in the Great Seal Patent
Office on the 18th August 1880.
ALEXANDER MCLEAN and GEORGE GREEN, both of Bankside, in the Borough of
Southwark. "AN IMPROVED MODE OF PRODUCING ORNAMENTAL SLABS AND
PANELS."
The object of our Invention is to produce ornamental slabs in various colors, and
with any variety of pattern, to be used for mural or other internal decoration in a
cheap and easy manner.
In carrying out our Invention we prepare a slab of plaster of Paris, of the size of
the ornamental slab required, and having obtained a perfectly smooth surface we
transfer onto it a design or picture in outline in any convenient manner, and incise
the lines with a graver or other tool to a depth of, say, one sixteenth of an inch,
and thereby form a mould.
We prefer to effect this operation after the slab of plaster has been made about
twelve hours, that is to say, after it has become thoroughly set, but before it
becomes quite hard and dry, as the slab when in the latter state, under the action
of the graver or other tool, would chip, and thus a jagged and unsightly outline
would be producod.
The engraved slab of plaster, when perfectly hard and dry, we coat or saturate
with a preparation of shellac, oil, or other substance which will render the slab of
plaster non-absorbent. From the mould, formed as above described, we take a
cast in cement (preferably Kecne's), or it may be paper pulp or other suitable
material.
When this cast is removed from the mould it will constitute a plate with the
outlines of the design or picture in relief.
This cast is now to be used as a mould, from which any number of slabs for
mural or other decoration may be made, but preparatory to its use it should be
coated with shellac or other varnish, which operation must be repeated each time
before taking a fresh cast.
In employing the mould we fill the space circumscribed by the design with
cement (in a plastic state) of any desired color, to a depth of, say, one eighth of
an inch. We next cover the whole slab evenly with cement of another color to
any desired thickness to form the groundwork of the picture, and also the back of
the slab intended to be made.
As soon as the cement has hardened we remove the slab from the mould and
place it upon a flat table. The slab is then carefully examined, and any air holes
are filled up and blemishes made good, and it is carefully rubbed down with stone
until it has a perfectly smooth and even surface.
We have now obtained an ornamented slab containing the body of the picture
or design, and the ground work, but without a filled up outline, as this remains
in intaglio.
To fill in the outline we use by preference a dark colored cement, which while
in a plastic state we smear over the picture or design, taking caro that all the lines
shall be properly filled in. We then remove the superfluous cement with a straight
edge or a sponge, and when dry the picture is completed.
The slab may then be polished in any convenient manner, and it will when
inserted in place form a very effective style of decoration.
It will be obvious that the number and shades of the colors used may vary
according to taste, for instance, the picture may be made in white on a plain or
marbled ground, or vice versa, the outlines being in black or brown.
In place of plaster of Paris for the first mould we may use slabs of soft wood,
soft stone, clay in a soft state, or any other suitable material that can be readily

page_text: cut into with a graver or other tool, and will give sharp lines, and the first cast
may likewise be formed of any suitable material that will, after being in a plastic
state, set hard.
By the use of this Invention slabs or panels for mural or other internal decora-
tion, or for tables and other purposes, may be made from original designs by the
architect, in accordance with the style of the building he is erecting, or in accordance
with any approved style of decoration in a cheap and easy manner, and the whole
of the design may generally be carried out on one slab instead of on many, as with
tiles, thus avoiding the junction lines across the design caused by joining
the tiles.
Having now described our Invention for an improved mode of producing
ornamental slabs or panels, and explained the manner of carrying the same
into effect, we wish it to be understood that under the above in part recited
Letters Patent we claim,-
Producing slabs or panels for decorative purposes in imitation of incised or inlaid
work in the manner hercin described.
In witness whereof, I, the said Alexander MoLean, have hereunto set my
hand and seal, the Seventeenth day of August, in the year of our Lord One
thousand eight hundred and eighty.