IMPROVEMENTS IN PRODUCING RELIEVOS WITH EQUALLY DEEPENED EXCAVATIONS."
Year: 1882

page_text: LETTERS PATENT to Ludwig Hermann Philippi of Hamburg Germany for
an Invention of "IMPROVEMENTS IN PRODUCING RELIEVOS WITH EQUALLY
DEEPENED EXCAVATIONS."
PROVISIONAL SPECIFICATION left by the said Ludwig Hermann Philippi
at the Office of the Commissioners of Patents on the 25th September 1882.
LUDWIG HERMANN PHILIPPI of Hamburg Germany "IMPROVEMENTS
PRODUCING RELIEVOS WITH EQUALLY DEEPENED EXCAVATIONS
"
"
IN
This Invention relates to improvements in relievos which are produced by
etching, and my object is to etch the figures of such relievos to an uniform and
equal depth.
To attain this object I cover a plate made of any suitable material that will not
be affected or corroded by the etching acid, with a layer of the material to be
etched. I thereby observe that such layer is spread equally over the plate and of
an uniform thickness.
Then I cover the layer with a protecting couch of etching-varnish, gelatine,
printing ink or other similar materials which is afterwards removed at all the
places where the layer is to be etched. When a plate thus prepared is exposed to
the etching acid, the upper layer will be eaten away at all the points that are not
covered by the protecting couch, but the excavations thus produced cannot go
further down or penetrate further than the non-corrosive base.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Ludwig Hermann Philippi in the Great Seal Patent Office on
the 22nd March 1883.
LUDWIG HERMANN PHILIPPI of Hamburg, Germany
PRODUCING RELIEVOS WITH EQUALLY DEEPENED EXCAVATIONS
$
"
»
IMPROVEMENTS IN
My invention relates to improvements in relievos which are produced by
etching and the object of my improvements is to etch the figures of such relievos
to an uniform and equal depth.
To attain this object I cover a plate made of any suitable material that will not
be affected or corroded by the etching acid, with a layer of the material to be
etched. I thereby observe that such layer is spread equally over the above non-
corrosive base-plate and of an uniform thickness. Then I cover the layer with a
protecting couch of etching-varnish, gelatine, printing-ink etc, which is afterwards
removed at all the places where the layer is to be etched in order to produce the
design on the plate. The design may be transferred on such protecting couch by
several means: when the protecting layer consists of etching varnish it is to be
scraped off on the places to be etched; when chromatized gelatine is employed the
places to be deepened are to be covered against the influence of light and the
gelatine then washed out; instead of chromatized gelatine also a solution of
asphaltum may be used and the photograph produced thereon; or the design may
be printed on the layer by employing a very consistent printing ink.
When a
plate thus prepared is exposed to the etching acid the upper layer will be eaten
away at all the points that are not covered by the protecting couch, but the excava-
tions thus produced cannot go further down or penetrate further than to the non-
corrosive base..
Having thus fully described the nature of my Invention I would have it under-
stood that what I claim is :-
The process of producing relievos with equally deepened design-lines by means of
a plate of corrosible metal deposed on a non-eorrosive base substantially in the
manner as set forth.
In. witness whereof I the said Ludwig Hermann Philippi have hereunto set
my hand and seal this Nineteenth day of March One thousand eight
hundred and eighty three.
LUDWIG HERMANN PHILIPPI.. (L.S.)