Year: 1886

page_text: Date of Application, 19th Mar., 1886.
Complete Left, 16th Dec., 1886.
Complete Accepted, 18th Jan., 1887.
ALEXANDER THOMSON of 8 Princess Street, Manchester, in the County of
Lancaster, Manufacturing Stationer, do hereby declare the nature of my invention to
be as follows:-
The object of this invention is to manufacture envelopes and by preference those
made of thin paper and suitable for foreign postal purposes through which it shall be
difficult if not impossible to decipher the writing of the letter or other contents covered
by such envelope.
In performing my invention I print or otherwise form a pattern on the inside
surface of the envelope, such pattern being composed for instance say of parallel lines
in close contact and which cross each other so that such lines are sufficiently visible
through the envelope to render writing characters as seen through or between them
perfectly illegible.
JOHN G. WILSON,
Agent for the Applicant.

page_text: Improvements in the Manufacture of Envelopes.
I ALEXANDER THOMSON of 8 Princess Street, Manchester, in the County of
Lancaster, Manufacturing Stationer, do hereby declare the nature of my invention and
in what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
The object of this invention is to manufacture envelopes and by preference those
made of thin paper and suitable for foreign postal purposes through which it shall be
difficult if not impossible to decipher the writing of the letter or other contents
covered by such envelopes.
In performing my invention I print or otherwise form on the inside surface of the
envelope, such pattern being composed for instance say of parallel lines in close con-
tact and which cross each other so that such lines are sufficiently visible through the
envelope to render writing characters as seen through or between them perfectly
illegible.
And in order that this my said invention may be the more readily understood I
hereunto annex a drawing illustrating the inner surface of an envelope shewing how
the same is printed with a series of parallel lines in close contact and crossing each
other in accordance with my invention.
I find it most convenient to lithograph this pattern or any similar pattern consisting
of lines sufficiently close together to give the desired confusing effect upon the inner
surface or side of the paper from which my improved envelopes are cut but it will be
apparent that woodcuts, blocks or engraving plates may be employed for printing the
inner surface of envelopes but these I should consider to be modifications of my inven-
tion. I prefer that the crossed lines or pattern employed shall be printed or otherwise
produced in black but it will be obvious that a more or less similar effect could be
obtained by employing other colors a preference being had for those colors which are
sufficiently visible through the envelopes to render writing characters as seen through
or between them perfectly illegible.
Having thus particularly described and ascertained the nature of my invention, I
declare that what I claim is :-
The improvements in the manufacture of envelopes substantially as and for the
purposes herein before described.