All Topics  
Bakelite

 

   Email Print
   Bookmark   Link






 

Bakelite



 
 
Bakelite is a material based on the thermosetting
Thermosetting plastic

Thermosetting plastics are polymer materials that irreversibly Curing form. The cure may be done through heat , through a chemical reaction , or irradiation such as electron beam processing....
 phenol formaldehyde resin
Phenol formaldehyde resin

The earliest commercial synthetic resin is based on a Phenol formaldehyde resin with the commercial name Bakelite, and is formed from an elimination reaction of phenol with formaldehyde....
 polyoxybenzylmethylenglycolanhydride, developed in 1907–1909 by Belgian
Demographics of Belgium

This article is about the demographics features of the population of Belgium, including population density, Ethnic group, education level, health of the populace, economic status, religious affiliations and other aspects of the population....
 Dr. Leo Baekeland
Leo Baekeland

Leo Hendrik Baekeland was a Demographics of Belgium chemist who invented Velox photographic paper and Bakelite , an inexpensive, nonflammable, versatile, and popular plastic....
. Formed by the reaction under heat and pressure of phenol
Phenol

Phenol, also known as carbolic acid, is a toxic, white crystalline solid with a sweet tarry odor, commonly referred to as a "hospital smell"....
 (a toxic, colourless crystalline solid) and formaldehyde
Formaldehyde

Formaldehyde is a chemical compound with the chemical formula H2CO. It is the simplest aldehyde. Formaldehyde exists in several forms aside from H2CO: the cyclic trimer trioxane and the polymer Polyoxymethylene....
 (a simple organic compound), generally with a wood flour
Wood flour

Wood flour is finely pulverized wood that has a consistencey fairly equal to sand, but can vary considerably, with particles ranging in size from a fine powder to roughly the size of a grain of rice....
 filler, it was the first plastic
Plastic

Plastic is the general common term for a wide range of synthetic or semisynthetic organic chemistry solid materials suitable for the manufacture of industrial products....
 made from synthetic components. It was used for its electrically nonconductive
Nonconductor

Nonconductors or electrical insulation are materials which lack movable electric charges, and which therefore lack a low-resistance path for charge flow....
 and heat-resistant properties in radio and telephone casings and electrical insulators, and was also used in such diverse products as kitchenware
Kitchenware

Kitchenware include utensils, appliances, dishes, cookware, and so on for use in the kitchen.See:*List of food preparation utensils* List of Japanese cooking utensils...
, jewellery
Jewellery

Jewellery is an item of personal adornment, such as a necklace, ring , brooch or bracelet, that is worn by a person. It may be made from gemstones or precious metals, but may be from any other material, and may be appreciated because of geometric or other patterns, or meaningful symbols....
, pipe stems, and children's toy
Toy

A toy is an object used in Play . Toys are usually associated with children and pets, but it is not unusual for adult humans and some non-Domesticationated animals to play with toys....
s.






Discussion
Ask a question about 'Bakelite'
Start a new discussion about 'Bakelite'
Answer questions from other users
Full Discussion Forum



Encyclopedia


Bakelite is a material based on the thermosetting
Thermosetting plastic

Thermosetting plastics are polymer materials that irreversibly Curing form. The cure may be done through heat , through a chemical reaction , or irradiation such as electron beam processing....
 phenol formaldehyde resin
Phenol formaldehyde resin

The earliest commercial synthetic resin is based on a Phenol formaldehyde resin with the commercial name Bakelite, and is formed from an elimination reaction of phenol with formaldehyde....
 polyoxybenzylmethylenglycolanhydride, developed in 1907–1909 by Belgian
Demographics of Belgium

This article is about the demographics features of the population of Belgium, including population density, Ethnic group, education level, health of the populace, economic status, religious affiliations and other aspects of the population....
 Dr. Leo Baekeland
Leo Baekeland

Leo Hendrik Baekeland was a Demographics of Belgium chemist who invented Velox photographic paper and Bakelite , an inexpensive, nonflammable, versatile, and popular plastic....
. Formed by the reaction under heat and pressure of phenol
Phenol

Phenol, also known as carbolic acid, is a toxic, white crystalline solid with a sweet tarry odor, commonly referred to as a "hospital smell"....
 (a toxic, colourless crystalline solid) and formaldehyde
Formaldehyde

Formaldehyde is a chemical compound with the chemical formula H2CO. It is the simplest aldehyde. Formaldehyde exists in several forms aside from H2CO: the cyclic trimer trioxane and the polymer Polyoxymethylene....
 (a simple organic compound), generally with a wood flour
Wood flour

Wood flour is finely pulverized wood that has a consistencey fairly equal to sand, but can vary considerably, with particles ranging in size from a fine powder to roughly the size of a grain of rice....
 filler, it was the first plastic
Plastic

Plastic is the general common term for a wide range of synthetic or semisynthetic organic chemistry solid materials suitable for the manufacture of industrial products....
 made from synthetic components. It was used for its electrically nonconductive
Nonconductor

Nonconductors or electrical insulation are materials which lack movable electric charges, and which therefore lack a low-resistance path for charge flow....
 and heat-resistant properties in radio and telephone casings and electrical insulators, and was also used in such diverse products as kitchenware
Kitchenware

Kitchenware include utensils, appliances, dishes, cookware, and so on for use in the kitchen.See:*List of food preparation utensils* List of Japanese cooking utensils...
, jewellery
Jewellery

Jewellery is an item of personal adornment, such as a necklace, ring , brooch or bracelet, that is worn by a person. It may be made from gemstones or precious metals, but may be from any other material, and may be appreciated because of geometric or other patterns, or meaningful symbols....
, pipe stems, and children's toy
Toy

A toy is an object used in Play . Toys are usually associated with children and pets, but it is not unusual for adult humans and some non-Domesticationated animals to play with toys....
s. In 1993 Bakelite was designated an ACS National Historical Chemical Landmark
ACS National Historical Chemical Landmarks

The National Historic Chemical Landmarks Program was launched by the American Chemical Society in 1992 and has recognized more than 60 landmarks to date....
 in recognition of its significance as the world's first synthetic plastic.

The retro appeal of old Bakelite products and labor intensive manufacturing has made them quite collectible in recent years.

Bakelite AG (a German company) claims to own the trademark in the following countries: Argentina
Argentina

Argentina, officially the Argentine Republic , is a country in South America, constituted as a federation of 23 provinces and an autonomous city....
, Australia
Australia

Australia, officially the Commonwealth of Australia, is a country in the southern hemisphere comprising the Australia of the world's smallest continent, the major island of Tasmania, and numerous list of islands of Australia in the Indian Ocean and Pacific Oceans....
, Austria
Austria

Austria , officially the Republic of Austria , is a landlocked country in Central Europe. It borders both Germany and the Czech Republic to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the west....
, Bangladesh
Bangladesh

, officially the People's Republic of Bangladesh is a country in South Asia. It is bordered by India on all sides except for a small border with Burma to the far southeast and by the Bay of Bengal to the south....
, Belgium
Belgium

* A small German-speaking Community of Belgium exists in eastern Wallonia. Belgium's linguistic diversity and related political and cultural conflicts are reflected in the history of Belgium and a complex Communities and regions of Belgium....
, China
China

China is a Culture of China, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....
, Cuba
Cuba

The Republic of Cuba is a country in the Caribbean. It consists of the island of Cuba , the island of Isla de la Juventud, and several adjacent small islands....
, Czech Republic
Czech Republic

The Czech Republic , is a landlocked country in Central Europe. The country borders Poland to the northeast, Germany to the west, Austria to the south and Slovakia to the east....
, Egypt
Egypt

Egypt is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Western Asia. Covering an area of about , Egypt borders the Mediterranean Sea to the north, the Gaza Strip and Israel to the northeast, the Red Sea to the east, Sudan to the south and Libya to the west....
, France
France

France , officially the French Republic , is a country whose Metropolitan France is located in Western Europe and that also comprises various Overseas departments and territories of France....
, Germany
Germany

Germany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium, and the Netherlands....
, Greece
Greece

Greece , officially the Hellenic Republic , is a country in southeastern Europe, situated on the southern end of the Balkans. It has borders with Albania, Bulgaria and the former Yugoslav Republic of Macedonia to the north, and Turkey to the east....
, Hungary
Hungary

Hungary , officially in English the Republic of Hungary , is a landlocked country in the Carpathian Basin of Central Europe, bordered by Austria, Slovakia, Ukraine, Romania, Serbia, Croatia, and Slovenia....
, India
India

India, officially the Republic of India , is a country in South Asia. It is the List of countries and outlying territories by total area country by geographical area, the List of countries by population country, and the most populous liberal democracy in the world....
, Ireland
Ireland

Ireland is the List of islands by area in Europe, and the twentieth-largest island in the world. It lies to the north-west of continental Europe and is surrounded by hundreds of islands and islet....
, Israel
Israel

Israel officially the State of Israel , is a country in the Middle East located on the eastern shore of the Mediterranean Sea. It borders Lebanon in the north, Syria in the northeast, Jordan in the east, and Egypt on the southwest, and contains geographically diverse features within its relatively small area....
, Italy
Italy

Italy , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia....
, Liechtenstein
Liechtenstein

The Principality of Liechtenstein is a Landlocked country#Doubly landlocked country alpine country microstate in Western Europe, bordered by Switzerland to the west and by Austria to the east....
, Luxembourg
Luxembourg

Luxembourg , officially the Grand Duchy of Luxembourg , is a small landlocked country in western Europe, bordered by Belgium, France, and Germany....
, Republic of Macedonia
Republic of Macedonia

The Republic of Macedonia , , often referred to simply as Macedonia, is a landlocked country on the Balkans in southeastern Europe. It is bordered by Serbia to the north, Bulgaria to the east, Greece to the south and Albania to the west....
, Malaysia
Malaysia

Malaysia is a federation that consists of States of Malaysia in Southeast Asia with a total landmass of . The capital city is Kuala Lumpur, while Putrajaya is the seat of the federal government....
, Morocco
Morocco

Morocco , officially the Kingdom of Morocco , is a country located in North Africa with a population of nearly 34 million and an area just under 447,000 km2....
, the Netherlands
Netherlands

The Netherlands is a country that is part of the Kingdom of the Netherlands. It is a parliamentary democratic constitutional monarchy. The Netherlands is located in North-West Europe, and bordered by the North Sea to the north and west, Belgium to the south, and Germany to the east....
, New Zealand
New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses , and numerous Islands of New Zealand, most notably Stewart Island/Rakiura and the Chatham Islands....
, Norway
Norway

Norway , officially the Kingdom of Norway, is a constitutional monarchy in Northern Europe that occupies the western portion of the Scandinavian Peninsula....
, Pakistan
Pakistan

Pakistan , officially the Islamic Republic of Pakistan, is a country located in South Asia and borders Central Asia and the Middle East. It has a 1,046 kilometre coastline along the Arabian Sea and Gulf of Oman in the south, and is bordered by Afghanistan and Iran in the west, India in the east and People's Republic of China in th...
, Switzerland
Switzerland

Switzerland is a landlocked Swiss Alps country of roughly 7.7 million people in Western Europe with an area of 41,285 km?. Switzerland is a federal republic consisting of 26 states called Cantons of Switzerland....
, Singapore
Singapore

Singapore , officially the Republic of Singapore, is an island country microstate located at the southern tip of the Malay Peninsula. It lies 137 kilometres north of the equator, south of the Malaysian state of Johor and north of Indonesia's Riau Islands....
, Slovakia
Slovakia

Slovakia . It was amended in September 1998 to allow direct election of the president and again in February 2001 due to EU admission requirements....
, South Africa
South Africa

The Republic of South Africa, also known by Official names of South Africa, is a country located at the southern tip of the continent of Africa....
, Spain
Spain

Spain or the Kingdom of Spain , is a country located in Southern Europe on the Iberian Peninsula.The Spanish constitution does not establish any official denomination of the country, even though Espa?a , Estado espa?ol and Naci?n espa?ola are used interchangeably....
, Sri Lanka
Sri Lanka

Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is an island country in South Asia, located about off the southern coast of India....
, Taiwan
Taiwan

Taiwan is an island in East Asia. "Taiwan" is also commonly used to refer to the country governed by the Republic of China and to the ROC itself, which governs the island of Taiwan, Orchid Island and Green Island, Taiwan in the Pacific Ocean off the Taiwan coast, the Penghu islands in the Taiwan Strait, and Kinmen and the Matsu Islands...
, Thailand
Thailand

The Kingdom of Thailand is an independent country that lies in the heart of Southeast Asia. It is bordered to the north by Laos and Myanmar, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the west by the Andaman Sea and Myanmar....
, Tunisia
Tunisia

Tunisia , officially the Tunisian Republic , is a country located in North Africa. It is bordered by Algeria to the west and Libya to the southeast....
, and the United Kingdom
United Kingdom

The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom , the UK or Britain,is a sovereign state located off the northwestern coast of continental Europe....
.

History

Bakelit Struktur
The Bakelite Corporation was formed in 1922 after patent litigation favorable to Baekeland from a merger of three companies: the General Bakelite Company, which Baekeland had founded in 1910, the Condensite Company founded by J.W. Aylesworth, and the Redmanol Chemical Products Company founded by L.V. Redman.

The American Catalin Corporation acquired the Bakelite formulas in 1927 and currently manufactures Bakelite cast resins.

Bakelite Limited was formed in 1926 from the amalgamation of three suppliers of phenol formaldehyde materials: the Damard Lacquer Company Limited of Birmingham
Birmingham

Birmingham is a city status in the United Kingdom and metropolitan borough in the West Midlands of England. Birmingham is the most populous of England's English Core Cities Group, and is the List of United Kingdom cities by population British city after London, with a population of 1,010,200 ....
; Mouldensite Limited of Darley Dale and Redmanol Chemical Products Company of London
London

London is the capital of both England and the United Kingdom, and the most populous municipality in the European Union. An important settlement for two millennia, History of London goes back to its founding by the Roman Empire....
. Around 1928 a new factory opened in Tyseley
Tyseley

Tyseley is a district in the southern half of the city of Birmingham, England, near the Coventry Road and the districts of Small Heath, West Midlands and Yardley, Birmingham....
, Birmingham, England (subsequently demolished in 1998). In 1939 the company was acquired by the Union Carbide and Carbon Corp
Union Carbide

Union Carbide Corporation is one of the oldest chemical and polymers companies in the United States, currently employing more than 3,800 people....
oration.

Properties

Phenolics are seldom used in general consumer products today due to the cost and complexity of production and their brittle nature. An exception to the overall decline is the use in small precision-shaped components where their specific properties are required, such as moulded disc brake cylinders, saucepan handles, electrical plugs and switches and electrical iron parts. Today, Bakelite is manufactured and produced in the form of sheets, rods and tubes for hundreds of industrial applications in the electronics
Electronics

Electronics refers to the flow of charge through nonmetal electrical conductor , whereas electrical refers to the flow of charge through metal electrical conductor....
, power generation and aerospace
Aerospace

Aerospace comprises the atmosphere of Earth and surrounding outer space. Typically the term is used to refer to the industry that researches, designs, manufactures, operates, and maintains vehicles moving through Aircraft and Space exploration....
 industries, and under a variety of commercial brand names, including Garolite.

Phenolic sheet is a hard, dense material made by applying heat and pressure to layers of paper or glass cloth impregnated with synthetic resin. These layers of laminations are usually of cellulose paper
Paper

Paper is thin material mainly used for writing upon, printing upon or packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
, cotton
Cotton

Cotton is a soft, staple fiber that grows in a form known as a boll around the seeds of the cotton plant a shrub native to tropical and subtropical regions around the world, including the Americas, India and Africa....
 fabrics, synthetic yarn
Synthetic fiber

Synthetic fibers are the result of extensive research by scientists to improve upon naturally occurring animal and plant. In general, synthetic fibers are created by forcing, usually through extrusion, fiber forming materials through holes into the air, forming a thread....
 fabrics, glass fabrics
Fiberglass

Fiberglass, , is material made from extremely fine fibers of glass. It is used as a reinforcing agent for many polymer products; the resulting composite material, properly known as fiber-reinforced polymer or glass-reinforced plastic , is called "fiberglass" in popular usage....
 or unwoven fabrics. When heat and pressure are applied to the layers, a chemical reaction (polymerization
Polymerization

In polymer chemistry, polymerization is a process of reacting monomer molecules together in a chemical reaction to form three-dimensional networks or polymer chains....
) transforms the layers into a high-pressure thermosetting
Thermosetting plastic

Thermosetting plastics are polymer materials that irreversibly Curing form. The cure may be done through heat , through a chemical reaction , or irradiation such as electron beam processing....
 industrial laminated plastic. When rubbed, original Bakelite has a telltale odor.

Bakelite Phenolic is produced in dozens of commercial grades and with various additives to meet diverse mechanical, electrical and thermal requirements. Some common types include:

  • PAPER REINFORCED PHENOLIC NEMA XX per MIL-I-24768 PBG Normal electrical applications, moderate mechanical strength, continuous operating temperature of 250°F.


  • CANVAS REINFORCED PHENOLIC NEMA C per MIL-I-24768 TYPE FBM NEMA CE per MIL-I-24768 TYPE FBG Good mechanical and impact strength with continuous operating temperature of 250°F.


  • LINEN REINFORCED PHENOLIC NEMA L per MIL-I-24768 TYPE FBI NEMA LE per MIL-I-24768 TYPE FEI Good mechanical and electrical strength. Recommended for intricate high strength parts. Continuous operating temperature 250°F.


  • NYLON REINFORCED PHENOLIC NEMA N-1 per MIL-I-24768 TYPE NPG Superior electrical properties under humid conditions, fungus resistant, continuous operating temperature of 160°F.


Patents


  • '—Condensation product and method of making same
(After following the patent link, click on the "Images" button to view the patent. You will need a TIFF
Tagged Image File Format

Tagged Image File Format is a file format for storing raster graphics, including photographs and line art. It is now under the control of Adobe Systems....
 (.tif) viewer to view the patent.)

Applications and usage

Although it is no longer extensively used as an industrial manufacturing material, in the past Bakelite was used in myriad applications, such as saxophone
Saxophone

The saxophone is a conical-Bore transposing instrument musical instrument considered a member of the woodwind family. Saxophones are usually made of brass and are played with a Single-reed instrument mouthpiece similar to the clarinet....
 mouthpieces, cameras
Brownie (camera)

Brownie was the name of a long-running and extremely popular series of simple and inexpensive cameras made by Eastman_Kodak. The Brownie popularized low-cost photography and introduced the concept of the Snapshot ....
, solid-body electric guitars
Rickenbacker

Rickenbacker International Corporation, also known as Rickenbacker ), is an electric guitar manufacturer, notable for putting the world's first electric guitars into general production in 1932....
, rotary-dial telephone
Telephone

The telephone is a telecommunications device that is used to transmitter and receive electronically or digitally encoded sound between two or more people conversing....
s, early machine gun
Machine gun

A machine gun is a Automatic firearm mounted or portable firearm, usually designed to fire List of rifle cartridgess in quick succession from an Belt or large-capacity Magazine , typically at a rate of several hundred rounds per minute....
s, and appliance casings. It was at one point considered for the manufacture of coins, due to a shortage of traditional manufacturing material. In 1943, Bakelite and other non-metal materials were tested for usage as a penny
Cent (United States coin)

The United States one-cent coin is a unit of currency equaling one one-hundredth of a United States dollar. Its symbol is: ?. Its obverse and reverse has featured the profile of President of the United States Abraham Lincoln since 1909, the century of his birth....
 in the United States before the Mint
United States Mint

The United States Mint primarily produces circulating currency for the United States to conduct its trade and commerce. The main Mint facility is located in Philadelphia, Pennsylvania, and branch mint are located in Denver, Colorado; San Francisco, California; and West Point, New York....
 settled on zinc coated steel
1943 steel cent

The 1943 steel cent was a variety of the United States Cent which was struck in steel due to wartime shortages of copper....
.

The foremost usage of Bakelite today is as a substitute for porcelain
Porcelain

Porcelain is a ceramic material made by heating raw materials, generally including clay in the form of kaolin, in a kiln to temperatures between and ....
 and other opaque ceramics in applications where fine detail is unimportant (other thermoset resins can capture detail more finely when molded) and durability over traditional ceramic compounds is desired. As such, a main continuing use for bakelite is in the area of board and tabletop games. Devices such as billiard balls
Billiards

Cue sports are a wide variety of Game of skill generally played with a cue stick which is used to strike billiard balls, moving them around a Baize-covered billiards table bounded by rubber ....
, dominoes, Mahjongg tiles and other gaming tilesets, and movers/pieces for games like chess
Chess

Chess is a recreational and competitive game played between two Player . Sometimes called Western chess or international chess to distinguish it from History of chess and other chess variants, the current form of the game emerged in Southern Europe during the second half of the 15th century after evolving from similar, much older...
, checkers, and backgammon
Backgammon

Backgammon is a board game for two players in which the playing pieces are moved according to the roll of dice. A player wins by removing all of his pieces from the board....
, are constructed of Bakelite for the look, durability, fine polish, weight, and sound of the resulting pieces. Dice
Dice

A die is a small polyhedron object, usually cubic, used for generating Statistical randomnesss or other symbols. This makes dice suitable as gambling devices, especially for craps or sic bo, or for use in non-gambling tabletop games....
 are sometimes made of Bakelite for weight and sound, but the majority are made of a thermoplastic such as ABS
Acrylonitrile butadiene styrene

Acrylonitrile butadiene styrene is a common thermoplastic used to make light, rigid, molded products such as piping , musical instruments , golf club heads , automotive body parts, wheel covers, enclosures, protective head gear, airsoft Airsoft gun and toys, including Lego bricks....
. It is also used to make the presentation boxes of luxury Breitling
Breitling

Breitling is a brand of Swiss watches from Grenchen, Canton of Solothurn . The watchmaker offers Certified chronometer watchs designed primarily for aviation use, though most frequently worn as high-end luxury watches....
 watches. Bakelite is also sometimes used as a substitute for metal in the construction of firearm magazines.

Bakelite is also used in the mounting of metal samples in metallography
Metallography

Metallography is the science and art of preparing a metal surface for analysis by grinding, polishing, and Industrial etching to reveal Microstructure....
.

See also

  • Ansco panda
    Ansco panda

    The Ansco Panda was a simple child's bakelite box camera made by the Ansco camera corporation of Binghamton, New York in the 1950s. It looks like certain Kodak Brownie products and was designed to compete directly with the Brownies....
    —children's Bakelite box camera
  • Bayko
    Bayko

    Bayko was an England building model construction toy invented by Charles Plimpton, an early plastics engineer and entrepreneur in Liverpool. First marketed in United Kingdom it was soon exported throughout the Commonwealth of Nations and became a world wide brand between 1934 and 1967....
    —A construction set toy in which most of the parts were made of Bakelite
  • Catalin
    Catalin

    Catalin is a brand name for a thermosetting plastic popular in the 1930s. Chemically, it's a phenol formaldehyde resin. Catalin is a cast bakelite product, with a different manufacturing process than other types of bakelite resins ....
  • Novotext
    Novotext

    Novotext is a trade name for cotton textile-phenolic resin, essentially cotton-reinforced Bakelite. It was often used in car engines for gear wheels used to provide a direct drive to the camshaft as it is flexible and quiet-running....
  • Phenol formaldehyde resin
    Phenol formaldehyde resin

    The earliest commercial synthetic resin is based on a Phenol formaldehyde resin with the commercial name Bakelite, and is formed from an elimination reaction of phenol with formaldehyde....
  • Phenolic resin
    Phenolic resin

    Phenolic resin can include any of various synthetic thermosetting resins such as Bakelite, obtained by the reaction of phenols with simple aldehydes and used to make molded products, including billiards balls, laboratory countertops, and as coatings and adhesives....


External links

  • in Basel, Switzerland: one of the world's largest private collections can be visited in a special exhibition http://www.15squaredevergennes.com in Paris until August 2, 2008