Improvements in the Application of Sand Blast in Engraving and Etching.
Year: 1889

page_text: Date of Application, 1st June, 1889-Accepted, 27th July,
1889
CUMI LEIM DE MOITICATION.
Improvements in the Application of Sand Blast in Engraving and
Etching.
I, JOSEPH LEWIS MILLS, of Baldwin's Gardens Gray's Inn Road in the County
of Middlesex. Art-colour-printer do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement :-
In my Specification No. 9244 of 1888 I described means of Engraving, and Mezzo-
tinting for Printing Purposes. My present invention relates to a process whereby the
operations described in said Specification are applied together with the operations
herein described to Etching with acid. For this purpose I take a plain metal
plate and place upon the surface thereof which is intended to be etched a coating of
Brunswick Black Asphaltum, or any other suitable resist which can be removed by the
sand blast. Upon this coating of Brunswick Black or other suitable resist I place a
tracing of the picture to be etched, I then remove the coating wherever it is requisite
to do so with the sand-blast applied with the instrument referred to in the aforesaid
Specification and particularly described in my Specification! No. 10295 of 1888, used
as a free hand tool, or with any other suitable sand-blast apparatus, and afterwards I
etch with acid in the usual manner. I next clear off with turpentine or other suitable
medium the Brunswick Black or other suitable resist, and lastly I subject the plate to
the dry process of Mezzotinting and softening by sand blast described in my aforesaid
Specification No. 9244 of 1888.
I also take a plain metal plate, and place on the surface thereof which I propose to
etch a coating of Brunswick Black, Asphaltum, or other suitable acid resist which is
sensitive to the sand-blast. Upon this coating I place a tracing of the picture to be
etched, and following this tracing I stop out the high light of the picture with
gum, after which I apply the sand-blast to the whole surface in the manner described
by my aforesaid Specification No. 9244 of 1888, I repeat the stopping out and appli-
cation of the sand blast thereby obtaining the intermediate gradations of tint between
the high light and the black colour until the latter is attained as described by my said
Specification last herein referred to. At this stage of the operations I wash off with
water all the gum, and then etch with acid in the usual manner, and, afterwards I
clear off with turpentine or other suitable medium the Brunswick Black or other
suitable resist, and lastly 1 Mezzotint the plate with sand blast as described by my
aforesaid Specification No. 9244 of 1888.
Having now fully described and ascertained the nature of my said invention
and in what manner the same
is to be performed I declare that what I
claim is
1-For etching purposes the process hereinbefore described for removing by the
application of sand-blast the coating of Brunswick Black, Asphaltuin, or other suitable
resist placed on the metal plate substantially as hereinbefore specified.
2-For etching purposes the process herein before described of successively stopping
out within the tracing on the coating of Brunswick Black Asphaltum, or other
suitable resist and subjecting said coating to the sand-blast substantially as herein
specified.
3000
Paw
JOSEPH LEWIS MILLS.
P. O'Halloran,
20, High Holborn, Patent Agent for Applicant.