IMPROVEMENTS IN EMBOSSING AND DECORATING WINDOW AND OTHER GLASS
Year: 1885

page_text: We HENRY DOULTON of the Albert Embankment Lambeth in the County of
Surrey and JOHN SLATER of the Nile Street Works Burslem in the County of
Stafford Potters do hereby declare the nature of our invention for "IMPROVEMENTS
IN EMBOSSING AND DECORATING WINDOW AND OTHER GLASS" to be as follows:-
Heretofore painting on glass has ordinarily been performed with pigments
composed of metallic oxides combined with a flux or vitreous mixture in pro-
portions adapted to produce a highly fusible colored glass of the required hue and
this has been done in order that the fusing point of the pigment may be much
lower than the fusing point of the glass upon which the pigment is to be applied.
So that when the glass and pigment are subsequently exposed to heat the pigment
may fuse and adhere permanently to the glass before the glass commences to melt.
To so fuse the pigment the glass when painted has been placed on a flat shelf with
the painted side uppermost and has been exposed to heat in a kiln or muffle.
According to this invention in place of employing pigments which are more
readily fusible than the glass on to which they are to be applied as is usually done
in glass painting we employ pigments composed of metallic oxides admixed with
flux in such proportion that they are less fusible than the glass so that when
exposed to heat the glass shall partially melt before the pigment commences to fuse
and in order to support the glass when it is subsequently subjected to heat we
place it on to a surface composed of any sufficiently non vitrifiable material such
for example as calcined flint reduced to a fine powder and we also cover over the
painted surface with similar powdered material on to which another sheet of glass
may be similarly placed and so on for any desired number of sheets. Trays filled
in the above manner may be placed one over the other in a kiln or muffle and
heated therein to the required degree without bending or deforming the sheets of
glass. If the glass to be decorated is in other forms say for example in the form of
tumblers, wine glasses or bottles we entirely surround such articles with the non-
vitrifiable material both externally and internally so that when exposed to heat
they may remain unaltered in form,
As the sheets or other articles of glass become heated the glass gradually softens
and the pigments adhere to it but the pigments remain unaffected by the material
with which the glass is surrounded.

page_text: The colored designs may be produced upon the sheets or articles of glass by first
taking impressions from copper plate or other engravings upon tissue paper and
then transferring the said impression to the surface of the glass having first
prepared the glass by a coating of size such as is generally used for printing
transfers upon vitreous surfaces Portions of the design may also be painted with
the metallic oxides wherever it may be required to heighten the effect.
In addition to coloring glass in the above manner it may also be simultaneously
embossed by impressing upon the surface of the powdered substance upon which
the sheet of glass is to be placed a suitable design so that when the glass placed
upon it becomes softened by the action of the heat the glass may embed itself into
the cavities of the design and so produce an embossed or raised surface dead or
bright as may be desired Lace is a very suitable fabric with which to emboss the
non-vitrifiable surface Sheets of glass may also in the same manner be embossed
without being simultaneously colored and the surface of the embossed portions
may be deadened by subsequently grinding them on a grindstone.

page_text: .
Improvements in Embossing and Decorating Window and
:
other Glass.
We, HENRY DOULTON of the Albert Embankment Lambeth in the County of
Surrey and JOHN SLATER of the Nile Street Works Burslem in the County of
Stafford Potters 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:-
Heretofore painting on glass has ordinarily been performed with pigments
composed of metallic oxides combined with a flux or vitreous mixture in pro-
portions adapted to produce a highly fusible colored glass of the required hue and
this has been done in order that the fusing point of the pigment may be much
lower than the fusing point of the glass upon which the pigment is to be applied.
So that when the glass and pigment are subsequently exposed to heat the pigment
may fuse and adhere permanently to the glass before the glass commences to melt.
To so fuse the pigment the glass when painted has been placed on a flat shelf with
the painted side uppermost and has been exposed to heat in a kiln or muffle.
According to this invention in place of employing pigments which are more
readily fusible than the glass onto which they are to be applied as is usually done
in glass painting we employ pigments composed of metallic oxides admixed with
flux in such proportion that they are less fusible than the glass so that when
exposed to heat the glass shall partially melt before the pigment commences to fuse
and in order to support the glass when it is subsequently subjected to heat we
place it on to a surface composed of any sufficiently non vitrifiable material such
for example as calcined flint reduced to a fine powder and we also cover over the
painted surface with similar powdered material on to which another sheet of glass
may be similarly placed and so on for any desired number of sheets. Trays filled
in the above manner may be placed one over the other in a kiln or muffle and heated
therein to the required degree without bending or deforming the sheets of glass.
If the glass to be decorated is in other forms say for example in the form of
tumblers, wine glasses or bottles we entirely surround such articles with the non
vitrifiable material both externally and internally so that when exposed to heat
they remain unaltered in form.
As the sheets or other articles of glass become heated the glass gradually softens
and the pigments adhere to it but the pigments remain unaffected by the material
with which the glass is surrounded.
The colored designs may be produced upon the sheets or articles of glass by first
taking impressions from copper plate or other engravings upon tissue paper and
then transferring the said impression to the surface of the glass having first
prepared the glass by a coating of size such as is generally used for printing
transfers upon vitreous surfaces. Portions of the design may also be painted with
the metallic oxides wherever it may be required to heighten the effect.
In addition to coloring glass in the above manner it may also be simultaneously
embossed by impressing upon the surface of the powdered substance upon which

page_text: the sheet of glass is to be placed a suitable design so that when the glass placed
upon it becomes softened by the action of the heat the glass may embed itself into
the cavities of the design and so produce an embossed or raised surface dead or
bright as may be desired. Lace is a very suitable fabric with which to emboss the
non-vitrifiable surface. Sheets of glass may also in the same manner be embossed
without being simultaneously coloured and the surface of the embossed portions
may be deadened by subsequently grinding them on a grindstone.
Having now particularly described and ascertained the nature of our said
invention and in. what manner the same is to be performed we declare that what
we claim is :-
1. Our improvement in decorating window and other glass consisting in
applying to its surface pigments less fusible than the glass then laying the glass
on or embedding it in a powdered refractory material such as calcined flint and
finally firing it at a temperature sufficient to soften the glass and cause union
between it and the pigment substantially as described.
2. Our improvement in embossing or decorating window and other glass
consisting in laying the glass on a surface of powdered refractory material such
as calcined flint on which a design has been previously impressed and then firing
the glass at a temperature sufficient to soften it and cause it to conform to the
pattern on the surface on which it has been laid substantially as described. .
Doind & 7h 12-A1 1000