IMPROVEMENTS TIT " IN THE MANUFACTURE OF WASRADLE
Year: 1870

page_text: LETTERS PATENT to Charles Hermann Rost, of Dresden, in the
Kingdom of Saxony, but now residing at Gibson Square, Islington,
in the County of Middlesex, for the Invention of "IMPROVEMENTS
TIT
"
IN THE MANUFACTURE OF WASRADLE
DA
Sealed the 6th September 1870, and dated the 17th March 1870.
PROVISIONAL SPECIFICATION left by the said Charles Hermann Rost
at the Office of the Commissioners of Patents, with his Petition, on
the 17th March 1870.
I, CHARLES HERMANN ROST, of Dresden, in the Kingdom of Saxony,
5 but now residing at Gibson Square, Islington, in the County of Middlesex,
do hereby declare the nature of the said Invention for "IMPROVEMENTS
IN THE MANUFACTURE OF WASHABLE PAPERS," to be as follows:-
This Invention relates to the manufacture of washable paper suitable
for covering the walls and ceilings of apartments, for ornamenting the
covers of books and portfolios, and door and other panels, the object
being at once to improve the quality and reduce the cost of the manu-

page_text: facture.
Hitherto washable papers when prepared in the piece for the
market have been more or less brittle, and the soft dead surface required
could not be uniformly obtained. Moreover, when printing upon papers
prepared with a washable ground the impressed colours would not take a
smooth surface.
By my improvements I avoid these disadvantages, and I considerably
reduce the cost of the manufacture by combining with the pigment a
comparatively inexpensive material, which will partially displace the
more costly metallic base of the pigment.
In carrying out my Invention I take a fine pulverized chalk, say,
50lbs., and mix it with, say, 2lbs. of soft soap boiled in turpentine until
the chalk is tender and soft. To this mixture I add about 25lbs. of
grey lead, white lead, or zinc white, ground in linseed oil, and containing
a proper proportion of driers, and having mixed the same well together, I
add any desired mineral colours thereto suitable to the work in hand;
then by the aid of a grinding mill I effect an intimate admixture of the
ingredients and thin down the composition with turpentine to bring it
to the required consistency for working kindly. This paint I apply to
paper by means of brushes or preferably, by the use of a well known
machine, consisting of an elastic bed held at tension and over which is
placed an adjustable gauge or scraper, which permits of the paper
being drawn under it and spreads evenly on the surface thereof the
pigment which is applied from time to time to the paper at the back of
the scraper.
SPECIFICATION in pursuance of the conditions of the Letters Patent, 2
filed by the said Charles Hermann Rost in the Great Seal Patent
Office on the 17th September 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
HERMANN ROST, of Dresden, in the Kingdom of Saxony, but now
residing at Gibson Square, Islington, in the County of Middlesex, send 3
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of March, in the
year of our Lord One thousand eight hundred and seventy, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, 3

page_text: give and grant unto me, the said Charles Hermann Rost, Her special
licence that I, the said Charles Hermann Rost, my executors, adminis-
trators, and assigns, or such others as I, the said Charles Hermann
Rost, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN THE MANUFACTURE OF WASHABLE PAPERS," upon the condition
(amongst others) that I, the said Charles Hermann Rost, my executors or
administrators, by an instrument in writing under my, or their, or
one of their hands and seals, should particularly describe and ascertain
the nature of the said Invention, and in what manner the same was
to be performed, and cause the same to be filed in the Great Seal
Patent Office within six calendar months next and immediately after.
the date of the said Letters Patent.
NOW KNOW YE, that I, the said Charles Hermann Rost, do hereby
declare the nature of my said Invention, and in, what manner the
same is to be performed, to be particularly described and ascertained in
and by the following statement, reference being had to the Drawing
hereunto annexed, and to the letters and figures marked thereon (that is
to say):-
This Invention relates to the manufacture of washable and waterproof
paper suitable for covering the walls and ceilings of apartments, for
ornamenting the covers of books and portfolios, and door and other
panels, the object being at once to improve the quality and reduce the
cost of the manufacture. Hitherto washable waterproof wall papers
when prepared in the piece for the market have been more or less brittle,
and the soft dead surface required could not be uniformly obtained.
Moreover, when printing upon paper prepared with a washable ground
the impressed colors would not take a smooth surface.
By my improvements I avoid these disadvantages, and I considerably
reduce the cost of the manufacture by combining with the pigment a
comparatively inexpensive material which will partially displace the
more costly metallic base of the pigment.
In preparing for example a grey color for the ground of a washable
paper, I take of fine pulverized chalk fifty pounds, and I mix with it.
two pounds of soft soap, which has been previously boiled in eight pounds

page_text: of turpentine.
This stirring of this mixture I continue until a soft
plastic mass has been produced. To this mixture I add twenty-five
pounds of grey lead, white lead, or zinc white, ground in twelve pounds
of linseed oil with a proper proportion of dryers and having mixed the
same well together I add half a pound of ivory black; then by the aid
of a grinding mill I effect an intimate admixture of the ingredients,
and thin down the composition with turpentine to bring it to the
required consistency for working kindly. This paint may be applied to
lengths of paper such as those manufactured for paper hangings
(without any previous preparation of the "paper) by means of brushes,
but I prefer to use a modification of a well known spreading machine,
which consists of an elastic bed held at tension and over which is set a
guage or scraper which permits of the paper being drawn under it to
receive an even coating of ground color on its upper surface.
In the accompanying Drawing I have shewn in sectional elevation the
spreading machine which I prefer to employ.
In this Figure, A, A, is a framing in which are mounted two tension
rollers B, B', the former of which is placed higher than the other. Over
these rollers is stretched a sheet of leather, cloth, or other suitable matc-
rial C, which forms an inclined clastic bed for the reception of the paper D
to be coated. Above this bed is placed transversely a trough which is
charged with the ground color that is to be applied to the paper. This
trough is V-shaped in cross section, and it is made with a narrow opening
at bottom which allows of the color resting on the paper that is imme-
diately below it. This trough consists of an adjustable guage or scrapor
made fast to the framing, and pendent therefrom is a tin plate E¹
forming the back and sides of the trough. The scraper E hears on the
paper below the trough and gauges the amount of color to be taken up
by the paper in its traverse under the trough. The paper is drawn
forward by hand in the direction of the arrow, and the excess of colour
which it receives from the trough being removed by the guage or
scraper as the paper is drawn forward, the yield of the elastic table C
assisting its action, the paper will leave the machine evenly coated with
the ground color. As the lengths of coated paper leave the machine
they are hung upon rods in a drying room, and after having been
exposed in this room to the air for two or three days they are ready to
receive, a second and final coating. For this purpose the paper is passed
a second time through the spreading machine, and the paper having

page_text: been again dried it is ready to receive any ornamental device or pattern
that may be desired.
I have stated that when printing upon papers prepared with a
washable ground there is a difficulty in making the impressed colours
take a smooth surface, the patterns are thereby not only imperfectly
defined, but the intensity of the colours is greatly detracted from the
ground when a dark one being visible through the impressed colour. To
avoid this defect I prepare the printing color in the following way,
namely, I use substantially the same ingredients as those already
mentioned for preparing the ground color, and I mix them in or about
the same proportions, using any desired coloring matter in place of the
ivory black. To every pound of the color so prepared I add one ounce
of Chinese wax, or its equivalent dissolved in spirits of turpentine. This
addition will enable the colour to be transmitted of an even thickness
to the surface upon which it is intended to be impressed, and will
thereby ensure its lying evenly upon and covering the ground colour.
Having now set forth the nature of my Invention of "Improvements
in the Manufacture of Washable Papers," and explained the manner of
carrying the same into effect, I wish it to be understood that I do not
confine myself to the exact proportions of the ingredients above stated,
as they may be departed from to some extent without materially
affecting the result, but I claim, preparing paint or coloring matter
to be used in the manufacture of washable papers in the manner and for
the purpose above set forth.
In witness whereof, I, the said Charles Hermann Rost, have here-
unto set my hand and scal, the Fifteenth day of September, in
the year of our Lord One thousand eight hundred and seventy.
CHARLES HERMANN ROST. (L.S.)