Posts Tagged ‘stoneware’

Mar
20
Lighting Products - Knowledge Base

METALS: All metals conduct electricity (thus the need for a “ground” wire).

  • Brass: Mixture of copper (55%-95%) and zinc and sometimes lead (for strength). May also have some lead, tin, nickel, etc. Yellow brass has 70% copper.
  • Bronze: Alloy of copper and tin (25%) and sometimes lead, zinc, phosphorous.
  • Copper: Usually plated because it’s too soft to hold shape (unless its fairly thick). Known for its ability to conduct electricity and heat.

Brass, bronze, copper, aluminum, and chrome do not rust and resist corrosion, so they are often used for outdoor lights. A green or brown patina forms over time and helps prevent corrosion. A magnet will not adhere to brass, bronze, or pot metal.

  • Chrome: Hard brittle gray metal used to plate other metals to give them a shiny finish.
  • Pewter: Alloy of tin (95%) and copper or antimony (sometimes aluminum is substituted which is very light in weight).

Pewter, copper, and pure silver dent easily.

  • Tin: Soft and easy to bend. Will rust. Often used in solder.
  • Tôle: Hand-painting on tin.
  • Silver: Softer than gold and usually plated onto a harder metal.  Sterling silver is not good for lamps because it’s too soft.
  • Wrought iron: Pure iron mixed with a glass-like material so it can be “wrought” into shapes.  (Cast iron is too brittle and cannot be shaped). Iron must be covered with paint or lacquer to prevent rust and corrosion.
  • Cast Aluminum: Light in weight, resists corrosion, silvery-white metal.
  • Stainless Steel: Resists corrosion and rust. 10% chromium.
  • “Pot” Metal: a gray alloy that can be cast but snaps when bent. Cheapest of all metals.

CRYSTAL & GLASS

  • Rock Crystal: Natural quartz mined in quarries. Very expensive!
  • Crystal: 24%-30% lead oxide (Lead improves clarity and softens glass for cutting).
  • Strass (Swarovski) Crystal: most expensive and most “fire”
  • Soda Ash Crystal (Turkish, Heirloom, etc.): Next best thing
  • Czechoslovakian: Some lead but not much.
  • Italian Crystal: No lead, just cut glass. Used in antique reproductions.
  • Murano Glass: Combination of quartz, soda, sand, potassium, and lead oxide at very high temperature. Glass is blown and stretched by hand. Many floral and unique shapes in glass.
  • Glass: Sand, soda, and lime heated in furnace and then blown, pressed (molded), or “drawn” (re-shaped).
  • Pressed Glass: Seams usually visible.

POTTERY & PORCELAIN

  • Porcelain: Hard paste ware fired at highest temperature. Purest and most delicate pottery.
  • Bone China: Hardest and most translucent of all porcelains.
  • China: Soft paste porcelain fired at lower temperature.
  • Stoneware: Clay fired to state of vitrification, non-porous, doesn’t require glaze for durability. Hard, heavy pottery that has a glossy surface when fired, so is often not glazed.
  • Earthenware: Clay that is not vitrified (glassy). Usually finished with colorful glazes and baked at low temperature. Very soft and easy to chip.
  • Terra cotta: (Burnt earth) Clay baked without a glaze, very porous and soft.
  • Bisque (Biscuit): Pottery fired once but not glazed.
  • Tin-glaze Pottery: Lead glaze made by adding tin oxide to glaze to conceal clay colors (Italian Majolica, French Faience, English Delftware).

OTHER MATERIALS:

  • Marble: Pressure and heat cause limestone to form into marble.  Pure marble is white. Pink and red marble has iron in it. Black marble comes from carbon or graphite.  Green marble is from chlorite. Tiny calcite crystals in marble make it sparkle. Marble can be cut or carved.
  • Alabaster: Alabaster is hydrated calcium sulfate which deteriorates when exposed to weather. High temperature will cause it to turn chalky white and then brown. Alabaster is carved, then sanded and smoothed, and then sprayed with polyurethane to close the pores and prevent deterioration. The translucent type is used for lighting fixtures lit from within (bowls and shades and wall uplights). The semi-transparent type (which resembles rock crystal) is used for lamp bases and lamp parts.
  • Wood:
    1. Hardwood: Walnut, Oak. Rosewood, Cherry, Maple
    2. Softwood: Pine, poplar, redwood
  • Wicker and Rattan:
    1. Wicker is usually made from willow branches and twigs.
    2. Rattan is made from reedy stems of palms in East India or Africa.
  • Hydrocal and plaster:
    1. Plaster: A lime, water, and sand composition that hardens when dry.
    2. Hydrocal: plaster with an extra bonding agent
    3. Cement: Sand, gravel, silica, gypsum, etc. added to plaster of paris mixture and fired in a kiln.
  • Resin (Plastic): Synthetic compound that can be dyed and molded. Stronger than hydrocal and non-porous.

CARE OF MATERIALS:

  • Brass & Bronze:
    1. Lacquered: Wash with sudsy water, rinse, dry, and buff with soft dry cloth. An old cotton sock makes an excellent polishing cloth,
    2. Not lacquered, shiny finish:  Wash and then apply brass polish.  Let polish dry. Then buff with a soft cloth. Apply thin coat of paste wax or lemon oil after polishing.
    3. For aged finishes:  Mix rottenstone and linseed oil to form a heavy cream and apply with a soft cloth and rub. Wipe off excess and polish with a soft cloth.
    4. For heavy corrosion: Rub with lemon dipped in hot vinegar, and salt mixture, wash, and rinse.
  • Chrome: Wipe with cloth soaked in sudsy water, rinse, and buff with a clean soft cloth.  For corrosion, rub with extra-fine steel wool.
  • Copper: Same as brass except use copper polish on unlacquered objects.
  • Iron: Wipe with a damp cloth and dry.  For corrosion, rub with kerosene and fine steel wool.
  • Silver: Follow instructions for brass except use a polish that is for silver only.
  • Silver-leaf and gold leaf: Use a soft shaving brush instead of a cloth to clean to avoid tearing the finish. To brighten, moisten a cotton ball with dry cleaning fluid or onion juice and gently pat (DO NOT RUB). Dry thoroughly.
  • Pewter: Polish with jeweler’s rouge and buff to produce a mirror-like surface. Pewter oxidizes slowly and evenly (as opposed to tarnishes) when exposed to air and gradually develops a soft warm patina.
  • Nickel: Polish with household ammonia.
  • Alabaster: Use a damp (not wet) cloth and gently wipe clean. NEVER use detergents or abrasives.
  • Marble: Remove stains with a paste made from hydrogen peroxide (from the drug store), powdered whiting (from the paint store), and a few drops of ammonia. Rinse with water, buff dry, and apply furniture polish.

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Mar
20
Ceramics & Porcelain

CERAMICS: Ceramics are shaped from clay and then heated (fired) in a kiln to make them durable.  The material that ceramics are made of and the finishing process create the different grades of ceramics:

  1. PORCELAIN: Porcelain (also termed china) is considered the finest ceramic because of its white color and translucent quality (ability to let light through) and its strength.  It produces a bell-like ring when struck.  Porcelain is made from kaolin (a pure white clay made from decomposed granite) and petuntse powder or flint feldspar.  Three kinds of porcelain are hard-paste porcelain (fired at high temperatures so the body and glaze become one), soft-paste or frit porcelain (creamy in tone), and bone china (bone ash added for more translucency).
  2. STONEWARE: Stoneware is water-resistant  made from gray or light brown clay fired at extremely high temperatures which causes the surface to become glossy so it is often not glazed.  Most U.S. folk pottery is made of slat-glazed stoneware.
  3. EARTHENWARE: Earthenware is porous pottery made from a mixture of earthenware clays baked at a low temperature which allows them to be utilize the more colorful tin glazes.  They must be glazed to be waterproof. They are very soft and easy to break (majolica, delftware, faience).      Terra-cotta is an unglazed earthenware made from low-fired clay.  Creamware was a lead-glazed earthenware made from white clay mixed with calcined flint.

Decoration techniques for ceramics include:

  1. Handpainting
  2. Transfer printing (A copper plate is made and inked with ceramic pigment which is then transfered to paper in a press and then the paper is placed on the surface of the item.
  3. Decal (also decalcamania)
  4. Stencil (also called stampino)
  5. Enamel

The following are common styles of ceramics with their popular or most well-known description.

  • CANTON The most common Canton Chinese export porcelain has blue and white landscapes with a stylized border.
  • CAPO DI MONTE Capo di Monte is a soft-paste porcelain with molded relief fanciful figures in bright colors.
  • CELADON Celadon was an early Chinese stoneware varying in color from gray-green to yellow-green.
  • CLOISONNÉ Copper wire separates enamel colors made from glass paste pigments with metallic oxides.
  • CREAMWARE Popular lead-glazed earthenware made of Devonshire white clay mixed with flint.
  • DELFT (DELFTWARE) Delftware is a tin-glazed earthenware with an underglaze blue decoration.
  • DERBY Derby is English porcelain with freely drawn floral patterns or bird and landscape patterns with moth, butterfly, and fruit borders.
  • DOCCIA Doccia italian porcelain is most known for  its bas-relief deoration of classical subjects (shells, peasants, chreubs).
  • FAïENCE Faïence is a tin-glazed earthenware from France (also Germany and Scandinavia) with painted patterns in opaque bright colored glazes.
  • FAMILLE ROSE  Famille rose enamel uses a delicate opaque pink and metallic gold pigment with very precise drawings of flowers, birds, landscapes, tree trunks, and rocks.
  • IMARI Imari is most known for its navy blue and iron-red (rust) colors, gilding with black outlining, and large lidded trumpet vases.  Its motifs include oriental scenes, lotus flowers, and scroll borders.
  • KARATSU Freehand geometric patterns, grasses, and wisteria were painted in iron oxide on a whitish slip.  Japanese.
  • KUTANI Kutani has bold large scale motifs and geometric patterns often with red and gold.  Japanese.
  • MAJOLICA Majolica was an Italian tin-glazed earthenware molded in shapes of nature often whimsical with brillant colors of lead glaze.  Popular colors were yellow, orange, green, turquoise, blue, purple, brown, and black.
  • MAYAN Classic Mayan ware (from Middle America) included delicate figures, polychrome cylindrical vases with scenes and glyphs from Mayan manuscripts and molded scenes of everyday life.
  • MEISSEN Meissen porcelain urns from Germany had fanciful 3-D figures and porcelain flowers, 24K gold decoration, and white skin tones on figurines.
  • MING This blue and white ware had carefully planned arrangements of  dragons, scenes with people, peonies, lotus, and crysanthemums with foliage in decorative bands.  Vases were usually baluster or pear shaped.
  • OLD PARIS or PARIS This porcelain had elaborate scenic designs with lots of gold on handled urns.
  • RAKU Raku ware is shaped by hand in asymmetrical forms with thick dripping irregular glazes in shades of brown, grey, red, yellow or yellow-green.  The only decoration is the glaze poured along the jug with a portion always left unglazed.
  • ROSE MEDALLION Colorful oriental scenes with peopleor floral  butterfly, and bird decoration often with gilding.
  • SATSUMA Ornate floral and oriental scenes with raised gold enameling outlines.  Japanese.
  • SEVRES Sèvres soft porcelain has birds, bouquets, trophies, flowers and borders using colors such as raspberry, gold, cream, and blue.
  • STAFFORDSHIRE Staffordshire was English pottery with motifs of sporting dogs, folk figures, etc usually made in pairs.
  • TOBACCO LEAF Pattern of leaves and flowers in multicolors.
  • WEDGEWOOD Type of creamware (earthenware) with sculptured Greek and Roman ornamentation and a bisque finish.

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