IMPROVEMENTS IN THE PREPARATION OF ARTISTS' COLORS, AND A NEW VEHICLE FOR THE PIGMENTS USED IN PAINTING
Year: 1878

page_text: LETTERS PATENT to Richard Liebreich, of No. 16, Albemarle Street, Piccadilly?
for the Invention of "IMPROVEMENTS IN THE PREPARATION OF ARTISTS'
COLORS, AND A NEW VEHICLE FOR THE PIGMENTS USED IN PAINTING."
Scaled the 26th November 1878, and dated the 18th June 1878.
PROVISIONAL SPECIFICATION left by the said Richard Liebreich at the
Office of the Commissioners of Patents on the 18th June 1878.
"
RICHARD LIEBREICH, of No. 16, Albemarle Street, Piccadilly. IMPROVEMENTS.
IN THE PREPARATIONS OF ARTISTS' COLORS, AND A NEW VEHICLE FOR THE
PIGMENTS USED IN PAINTING."
The new vehicle is produced by dissolving a softer kind of gum copal or damar
in the essential oil of copaiva balsam, and in passing the solution through a filter.
This solution forms a nearly colourless bright transparent and very thick varnish.
The vehicle may be more or less diluted with the essential oil of copaiva, and will
then replace in an advantageous way the different kinds of natural balsam of
copaiva frequently used for the restoration of pictures and as an addition to
mediums for painting. The inconveniences of the natural balsam arc,--that it is
exceedingly variable in colour, consistency, &c., that the relative quantity of essential
oil it contains varies very much, and that the resinous substance which remains
after distilling the balsam is very soft and dark, and gradually with time becomes
more opaque and brownish. All these inconveniences are avoided in my vehicle, in
which the proportion between the oil and the gum can be easily determined, and in
which a harder colourless resin which does not darken with time replaces the
copaiva resin.
The new method of preparing colours with this new vehicle is as follows:-The
pigments, after having undergone the usual treatments of washing, drying, grinding, ·
&c., which reduce them to pure, fine, dry powder, are first ground with as little of
the essential oil of copaiva as possible; the quantity varies for different pigments,
but should be only just sufficient to transform the powder into a dry paste; this
Price 1

page_text: colours.
2nd. Using partly oil colours (those which require but a small quantity of oil
for grinding, especially white lead) and partly my colours, especially the transparent
ones.
3rd. Diluting the colours very much with rectified essence of turpentine, petroleum,
petroleum ether, benzine, or similar liquids, to imitate the technic of water colour
painting.
4th. Using addition mediums such as are used in painting with oil colours.
5th. Adding a mixture of turpentine, 1, 2, or 3 parts, and oil copal body varnish
1 part; the more turpentine the flatter, and the more varnish the more shining the
picture will be when finished. This 5th application is especially to be commended,
the colours so employed dry very quick. If slower drying is desirable, it will be
necessary to add the new vehicle diluted with copaiva oil.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Richard Licbreich in the Great Seal Patent Office on the 17th
December 1878.
RICHARD LIEBREICH, of No. 16, Albemarle Street, Piccadilly.
"IMPROVEMENTS
IN THE PREPARATION OF ARTISTS' COLORS, AND A NEW VEHICLE FOR THE
PIGMENTS USED IN PAINTING."
This Invention has for its object improvements in the preparation of artists'
colors, and a new vehicle for the pigments used in painting.
The new vehicle is produced by dissolving gum damar, which is known in the
French market as "copal tendre," in the essential oil of copaiva balsam, and passing
the solution through a filter. This solution forms a nearly colorless bright trans-
parent and very thick varnish.
I prefer to operate in the following manner :-The powdered gum is gradually
thrown into the cold oil, and it is kept constantly stirred, so as to avoid the glueing
together of the particles of gum. When this solution is saturated, that is to say,
when the oil copaiva has dissolved as large a quantity of gum as it is capable of
dissolving the solution is allowed to stand several days, so that all foreign substances
and all undissolved particles of the gum may sink down; the solution is then
filtered cold through a very coarse filtering paper.
•
This vehicle may be more or less diluted with the essential oil of copaiva, and
will then replace in an advantageous way the different kinds of natural balsam
copaiva frequently used for the restoration of pictures and as an addition to
mediums for painting. The inconveniences of tho natural balsam are that it is
exceeding variable in color, consistency, &c., that the relative quantity of essential
oil it contains varies very much, and that the resinous substance which remains
after distilling the balsam is very soft and dark, and gradually with time becomes
more opaque and brownish; all these inconveniences are avoided in my vehicle, in
which the proportion between the oil and the gum can be easily determined, and in
which a harder colourless resin which does not darken with time replaces the copaiva
resin.
The new method of preparing colors with this new vehicle is as follows:-The
pigments, after having undergone the usual treatinents of washing, drying, grinding,
&c., which reduced them to pure, fine, dry powder are first ground with as little
of the essential oil of copaiva as possible, the quantity varies for different pigments,
but should be only just sufficient to transform the powder into a dry paste; this
paste has to be ground very carefully; after this the new vehicle in its concentrated
form has to be added in different quantity, according to the nature of the pigment,
and only just sufficiently ground or mixed with the paste to make the mixture
quite even, the quantity to be added is practically determined by the consistency
which should be equal to that of the usual artists' oil colors, and slightly firmer in
the opaque than in the transparent colors, as in these latter a greater quantity of
resinous substance is admissible than in the opaque ones. The colors so prepared
are then immediately filled in tubes.
The purpose of my Invention is to form a complete or partial substitute for oil
colors, varnish colors, balsam colors, and to a certain degree, even for water
colors.
The advantage of my colors over the former is, that they avoid the incon-
veniences of fatty oil, which drys slowly, and in a very different way, according to
the nature of the pigment it is mixed with, and which forms with time an opaque
brownish substance, interfering very much with the preservation of the color of a
picture.
The advantage over ordinary varnish colors is in the clearness, transparency,
thickness, and elasticity of my vehicle.
The advantage over balsam colors has been explained before.

page_text: .
First. Using the colors by themselves in the same way as oil, varnish, or balsam
colors.
Second. Using partly oil colors (those which require but a small quantity of oil
for grinding, especially white-lead) and partly my colors, especially the transparent
ones.
Third. Diluting the colors very much with rectified essence of turpentine,
petroleum, petroleum ether, benzine, or similar liquids to imitate the technic of water
color painting.
Fourth. Using additional mediums such as are used in painting with oil colors.
Fifth. Adding a mixture of turpentine, one, two, or three parts, and oil copal
body varnish one part, the more turpentine the flatter, and the more varnish the
more shining the picture will be when finished. This fifth application is especially
to be commended, the colors so employed dry very quick. If slower drying is
desirable it will be necessary to add the new vehicle diluted with copaiva oil.
What I claim is,—
First. The new vehicle, consisting of gum damar or "copal tendre" dissolved in
oil of copaiva.
Second. The preparation of artists' colors by combining pigments with the said
vehicle..
In witness whereof, I, the said Richard Liebreich, have hereunto set my hand
and seal, this Twenty-ninth day of October, in the year of our Lord One
thousand eight hundred and seventy-eight.
לבד
R. LIEDREICH. (L.S.)