Putting Patterns on Porcelain

Today there are many options for putting colorfulsilica. This clay composition accounts for the pure
patterns onto porcelain china. Some, likewhite gleam of porcelain.
decoupage, waterslide decals and air-dry paints likeArtisans who paint porcelain (rather than actually
Delta Air-Dry PermEnamel are within the reach ofmake it) refer to three grades of porcelain:
any home crafter.hard-paste, soft-paste, and bone china. They all
Others, like dye sublimation printing, transfercontain kaolin but only hard-paste has feldspar and
printing and hand-glazing high-fired pottery requiresilica and is high-fired. The high temperatures
substantial investment in equipment and are bestcause the body and the glaze to fuse. When
suited to well-capitalized businesses and artists'hard-paste porcelain is broken, it is impossible to
cooperatives.distinguish the body from the glaze.
The two classic ways of putting patterns ontoSoft-paste porcelain adds ground glass or frit
porcelain, hand-painting and transfer printing, still(material for glass that is not yet fused and
exist today. In addition, there is a high-techvitrified) and is fired to between cone 01 and 1
version of waterslide decals used commercially(1999 to 2109 degrees F). Because soft-paste
which consists of screen-printing decals withporcelain is fired at lower temperatures, it does
glazes and applying the decals to the porcelain. Innot completely vitrify and remains slightly porous.
each case, the pottery is high-fired beforeWhen soft-paste porcelain is broken, you can
decorating to at least cone 6. [Cone is a measuredistinguish a grainy body covered with a glassy
of heat absorption resulting from heat appliedlayer of glaze.
over time. Cone 6 translates to between 2165Bone china has bone ash added to the kaolin and
and 2269 degrees F (depending on how fast thevitrifies (becomes glass-like) somewhere between
kiln heats - or ramps - up).] Such high-firingcone 2 and cone 5 (2034 to 2205 F). Though not
produces the hard almost-translucent quality ofas hard as true porcelain, bone china is more
genuine porcelain. Then the piece is decorated anddurable than soft-paste porcelain. The bone ash
lightly fired repeatedly to melt and fuse the glazesgreatly increases the translucence of the porcelain.
to the porcelain.Finally, go to a tile store and look at their
Incidentally, the term "porcelain" has been applied"porcelain" tiles. If you turn them over, you will
more and more broadly as new techniquessee base clay ranging from white to brown to
developed. Ask any potter to define "porcelain"gray. The definition of "porcelain" in the tile
and he will likely give you the classic definition. Toindustry has nothing to do with the clay content
a potter, genuine porcelain is high-fired (cone 6 oror level of firing. Rather, tile manufacturers define
higher) white clay that is at least somewhatas "porcelain" any tile fired to the point where it
translucent. It has a large proportion of kaolin clay,absorbs less than 3% moisture.
with the remainder being primarily feldspar and