IMPROVEMENTS IN THE MANUFACTURE OF CARDS, TABLETS. AND OTHER ARTICLES FROM WHICH MARKS MADE WITH INK OR LEAD PENCIL MAY BE REPEATEDLY ERASED BY MOISTURE WITHOUT INJURY TO THE SURFACE
Year: 1866

page_text: LETTERS PATENT to Henry Josiah Griswold, of Boston, Massachusetts,
United States of America, now of No. 8, Southampton Buildings,
Chancery Lane, in the County of Middlesex, for the Invention of
"IMPROVEMENTS IN THE MANUFACTURE OF CARDS, TABLETS. AND OTHER
ARTICLES FROM WHICH MARKS MADE WITH INK OR LEAD PENCIL MAY BE
REPEATEDLY ERASED BY MOISTURE WITHOUT INJURY TO THE SURFACE."
Sealed the 10th August 1866, and dated the 8th June 1866.
PROVISIONAL SPECIFICATION left by the said Henry Josiah Griswold
at the Office of the Commissioners of Patents, with his Petition, on the
8th June 1866.
1, HENRY JOSIAH GRISWOLD, of Boston, Massachusetts, United States of
America, now of No. 8, Southampton Buildings, Chancery Lane, in the
County of Middlesex, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN THE MANUFACTURE OF CARDS. TABLETS, AND OTHER
ARTICLES FROM WHICH MARKS MADE WITH INK OR LEAD PENCIL MAY BE REPEATEDLY
ERASED BY MOISTURE WITHOUT INJURY TO THE SURFACE," to be as follows:-
The said Invention consists, first, in covering printed or ruled cards, tablets,
or sheets of paper and cloth with a film of transparent substance which
protects without concealing the printed matter or ruled lines upon such card
or tablet, and which forms a surface for temporary writing or marking either
רנס'מ

page_text: with ink or pencil; and, second, in the employment of an improved com-
position for producing the transparent surface upon the said cards, tablets, or
other sheets, and also upon plain or blauk cards or tablets for memorandum
books and other like purposes.
The first part of the said Invention relates more especially to advertising
cards, price lists, skeleton maps, and other cards or sheets upon which it is
desired that the lines and printed matter should be permanent while other
words or characters should be readily erasable to admit of removal or
alteration. Attempts have been made to impart these properties to the said
cards and other articles by first covering the surface to be printed upon with
an opaque waterproof composition, and then printing or otherwise producing
the permanent matter or design upon the surface of the said composition upon
which the erasable characters were also formed. This method has, however,
been found very imperfect, as, though the pencil or ink marks could be
erased, the printed matter was also wholly or partially obliterated by the
moisture and friction applied to effect the required erasures. To obviate
these defects the printed matter or design is first produced upon the surface
of the card, tablet or other sheet of paper or cloth, which is then covered with
the transparent waterproof composition. After this has been allowed to dry a
smooth finish may be imparted to the card or other sheet by passing it
between suitable calender rolls. Writing or other marks in ink or pencil
may then be repeatedly produced upon and erased from the surface of the said
card without injury to the transparent covering or to the printed matter
underneath. The said ink or pencil marks are erased by slightly rubbing the
prepared surface with a damp sponge or cloth, or with the tips of the fingers
slightly moistened.
The composition for producing the transparent covering consists of finely
pulverized soapstone (lapis ollaris) or other stone or material, the particles of
which when finely reduced possess the required degree of roughness, and white
shellac or other transparent varnish. The proportions in whichthe above-named
ingredients are most advantageously combined are about five pounds of the
pulverized soapstone with eighteen pounds of the varnish. The mixture
sho uld be ground in a suitable mill until it is reduced to the required degree
of fineness, and is then applied in a liquid state to the surface of the card,
tablet, or other sheet. This composition when applied to blank cards, tablets,
memorandum books, and other similar articles will form a surface which can
be easily written upon in either ink or pencil, and the writing is readily erasable
and can be obliterated and renewed as often as desired without scratching,
soiling, or otherwise injuring the said surface. The said cards or sheets will

page_text: also form an excellent substitute for common school slates, porcelain slates"
and other similar articles.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Josiah Griswold in the Great Seal Patent Office
on the 7th December 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
JOSIAH GRISWOLD, of Boston, Massachusetts, United States of America, now
of No. S, Southampton Buildings, Chancery Lane,in the County of Middlesex,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighth day of June, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Henry Josiah Griswold, Her special licence that I, the said Henry
Josiah Griswold, ny executors, administrators, and assigns, or such others
as I, the said Henry Josiah Griswold, my exccutors, 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 CARDS, TABLETS, AND OTHER
ARTICLES FROM WHICH MARKS MADE WITH INK OR LEAD PENCIL MAY BE REPEATEDLY
ERASED BY MOISTURE WITHOUT INJURY TO THE SURFACE," upon the condition
(amongst others) that I, the said Henry Josiah Griswold, my executors or
administrators, by an instrumeut 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 Henry Josiah Griswold, 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: -
The said Invention relates to covering cards, tablets, or sheets of paper and
cloth, either printed, or ruled, or otherwise, with a film of transparent sub-
stauce which forms a surface for temporary writing or marking either with

page_text: ink or pencil, and protects without concealing the printed matter or ruled
lines (if any) upon such card or tablet. I employ for this purpose an
improved composition consisting of a waterproof transparent varnish combined
with a material of a gritty nature to cause the varnish surface to receive
freely the marks of a pen or pencil.
The Invention is especially applicable to advertising cards, price lists,
skeleton maps, and other cards or sheets upon which it is desired that certain
lines and printed matter should be indelible or permanent while other words
or characters should be readily erasable to admit of removal or alteration.
Attempts have been made to impart these properties to cards and other
articles by first covering the surface to be printed upon with an opaque water-
proof composition and then printing or otherwise producing the permanent
matter or design upon the surface of the said composition upon which the
erasable characters were also formed. This method has, however, been found
very imperfect, as, though the pencil or ink marks could be erased the
printed matter intended to be permanent was also wholly orpartially obliterated
by the moisture and friction applied to effect the required erasures. To
obviate these defects the indelible printed matter or design is first produced
upon the surface of the card, tablet, or other sheet of paper or cloth which is
then covered with the transparent waterproof composition. After this has
been allowed to dry a smooth finish may be imparted to the card or other
sheet by passing it between suitable calender rolls. Writing or other marks
in ink or pencil may then be repeatedly produced upon and erased from
the surface of the said card without injury to the transparent covering or
to the printed matter under it. The said ink or pencil marks are erased
from the prepared surface by simply rubbing the same with a damp sponge or
cloth, or with the tips of the fingers slightly moistened.
The composition which I prefer to employ for producing the transparent
covering consists of finely pulverized soapstone and white shellac varnish. I
dissolve three pounds of shellac in one gallon of the spirit called by drysalters
"finish," and I combine therewith one pound and a half of powdered soap-
stone. Other proportions may be employed, but having made numerous
experiments I believe those above stated to be the most suitable. The
mixture should be ground as fine as possible in a suitable mill such as is used
for grinding paint, and is then applied in a liquid state by means of a brush
to the surface of the card, tablet, or other sheet. This composition when
applied to blank cards, tablets, memorandum books, and other similar articles
will form a surface which can be easily written upon in either ink or pencil.
The writing is readily erasable, its obliteration and renewal being repeated as

page_text: often as desired without scratching, soiling, or otherwise injuring the said
surface. The said cards or sheets will also forin an excellent substitute for
common school slates, porcelain slates, and other similar articles. The cards.
tablets, or other surfaces may, if desired, be tinted before the composition is
applied. The soapstone employed should be as free from color as possible. I
prefer to use the white soapstone found in the United States of America. In
place of powdered soapstone other very fine grit may be employed, as, for
example, ground slate sufficiently free from color, but the soapstone is pre-
ferable. Other transparent waterproof varnish may be substituted for that
above set forth, but shellac dissolved in spirit succeeds well.
What I claim is the covering cards, tablets, and other similar surfaces
either printed, or ruled, or otherwise with a film of a transparent composition
consisting of a waterproof varnish mixed with powdered soapstone or other
finely divided gritty material.
In witness whereof, I, the said Henry Josiah Griswold, have hereunto
set my hand and seal, this First day of November, in the year of our
Lord One thousand eight hundred and sixty-six.
Witness,
GEORGE HASELTINE,
8, Southampton Buildings,
London, W.C.
H. J. GRISWOLD. (1..8.)