Graffiti: Types of graffiti
Street art and Post-Graffiti
In the 1980s and early 1990s the writers Cost and Revs became the first to get up with their name with the new techniques that would become a new form of graffiti, i.e. Post-Graffiti (a term which comes from the French artist Stak), also known as Street Art.
Street artists use media such as sticker, stencil, wheatpaste and poster, but also scratch, paint and put up installations in any urban space. They all have put up all such work illegally, but have various aims. Some follow the aim of a graffiti writer to get up with a name or -- more likely in Street Art -- with an image, others have a political aim.
Many just want the public to see their message. The word "Pray" has been scratched onto the walls of public telephone booths and entry doors to buildings all over New York City since the 1980s by an anonymous woman from Brooklyn, NY. The street art movement operates worldwide, for example, the '"Pochoir" stencil graffiti in Germany and France.
Since the 1990s Shepard Fairey has influenced many of today's street artists with his 'Obey Giant' campaign. Other important street artists include C6.org, who incorporate new technologies into street graffiti art, Banksy, probably the most famous of the stencil artists, D*Face (UK), Stak, HNT, Alexone, André (France), Swoon, famous for the cut-out poster technique, Faile collective, (USA), Branded (OPHOTN), Os Gemeos, Herbert (Brazil), 6-_-©IIIII>.4rtist.com, Flying Fortress, Gomes, Graffitilovesyou (Germany), Influenza, Erosie (Holland), El Tono Spain Ang Diwa FFK, Philippines and others.
6-_-©|||||>.4rtist.com originated a new form of tagging around 1995 in Berlin. He painted his 500 000 "6" tags with lime on wildly pasted posters, on garbage, and on the street. 30% of his tags he painted while cycling.
More recently, developments in technology and the rise in the availability of electronics have resulted in a new form of graffiti. Various techniques such as using projectors, LED throwies, and even pirate radio could all be considered "electronic graffiti". Other forms of electronic graffiti could include website defacement or uploading and/or printing files from computers in stores.
In contrast, a non-destructive form of graffiti has also evolved in the electronic age. This new form manifests itself in computer graphics applications designed for the specific purpose of virtual vandalism. The rationale behind these applications ranges from creative expression to office stress relief. One example is "Graffiti Playdo", which serves as an online virtual canvas accessible to graffitists world-wide. Another example is "Desktop Graffitist", which enables computer users to spray paint their screen, including their desktop and any other open windows.
Radical and political graffiti
Graffiti often has a reputation as part of a subculture that rebels against authority, although the considerations of the practitioners often diverge and can relate to a wide range of attitudes. We see graffiti not only as an art but also as a lifestyle. It can express a political practice and can form just one tool in an array of resistance techniques. One early example includes the political punk band Crass, who conducted a campaign of stencilling anti-war, anarchist, feminist and anti-consumerist messages around the London Underground system during the late 1970s and early 1980s.
The developments of graffiti art which took place in art galleries and colleges as well as "on the street" or "underground", contributed to the resurfacing in the 1990s of a far more overtly politicized art form in the subvertising, culture jamming or tactical media movements. These movements or styles tend to classify the artists by their relationship to their social and economic contexts, since graffiti art remains illegal in many forms, in most countries.
Contemporary practitioners, accordingly, have varied and often conflicting practices. Some individuals, such as Alexander Brener, have used the medium to politicise other art forms, and have used the prison sentences forced onto them as a means of further protest.
The practices of anonymous groups and individuals also vary widely, and practitioners by no means always agree with each others' practices. Anti-capitalist art group the Space Hijackers, for example, in 2004 did a piece about the contradiction between the capitalistic elements of Banksy and his use of political imagery. As an added complication to this picture, some artists receive a combination of government funding as well as commercial or private means, like irrational.org who recently coined the term Advert Expressionism, replacing the word Abstract for Advert, in Clement Greenberg's essay on Abstract Expressionism.
On top of the political aspect of graffiti as a movement, political groups and individuals may also use graffiti as a tool to spread their point of view. One can label this as "propaganda graffiti". This practice, due to its illegality, has generally become favored by groups excluded from the political mainstream (e.g. far-left or far-right groups) who justify their activity by pointing out that they do not have the money - or sometimes the desire - to buy advertising to get their message across, and that a 'ruling class' or 'establishment' control the mainstream press, systematically excluding the radical/alternative point of view. This type of graffiti can seem crude, for example fascist supporters often scrawl swastikas and other Nazi images. Because of the strong associations between Nazi images and racial violence, many see this type of graffiti as tantamount to a threat of violence, and thus some would classify it as a form of terrorism.
Both sides of the conflict in Northern Ireland produce political graffiti. As well as slogans, Northern Irish political graffiti include large naïve wall paintings, referred to as murals. Along with the flying of flags and the painting of kerb stones, the murals serve a territorial purpose. Artists paint them mostly on house gables or on the Peace Lines, high walls that separate different communities. The murals often develop over an extended period and tend to stylization, with a strong symbolic or iconographic content. Loyalist murals often refer to historical events dating from the war between James II and William III in the late 17th century, whereas Republican murals usually refer to the more recent troubles.
Following the recuperation of 'Post-Graffiti', illegal fly-posting provides another popular visual method by which political groups seek to spread their message and advertise their events. In the UK, posters advertising the February 15, protests against the 2003 invasion of Iraq stayed visible months after the event and may remain for years.
Since many people consider graffiti artists as vandals, many such artists have moved to creating computer generated graffiti instead, using computer graphics to mimic and expand on the styles of aerosol art. When they create such art on a computer, it does not technically count as graffiti, in the sense of something unauthorized, but it retains the name because of stylistic influences. Such art also does not count as computer-generated, in the sense of a computer program actually determining the design; rather it classes as computer-assisted, and generated by human artists. Most of these types of artists have associations with ASCII art, ANSI art, and the computer underground.
Computer-generated graffiti also appears commercially in the creation of realistic computer simulations of city environments, for example in video games such as Grand Theft Auto, or tagging can become part of the object of the game itself, as in Jet Set Radio, and The Warriors. Marc Ecko's Getting Up: Contents Under Pressure, a recent video game release, focuses on graffiti art as the main theme of the game.
Love expressions as graffiti are not rare. In most cases they are scrething in trees and small textes made by a waterproof pencil. However love expressions as big spraying can be also found sometimes, especially in the neighbourhood of motorways or railways.
With the expansion of the Internet some artists - such as Chu from central Birmingham - have turned their attention from the wall to the web. His art now appears in many diverse forms from community art works to flyers for hip hop nights in Britain. Chu sees himself as the first truly 3D artist of commercial merit. 
As technical graffiti one can desribe color markings showing which trees have to be felled by workers or where road workers have to tear open a street. This kind of graffity is in most cases temporary and will be destroyed at the work.
Other graffiti forms
Latrinalia; a very different sort of graffiti, appears in many public restrooms, such as those on university campuses. Such graffiti tends more toward the obscene than the artistic, including sexual propositions, vulgar insults, toilet humour, bawdy poetry, pornography, and the occasional crude cartoon. For photographic examples of bathroom graffiti see The Bathroom Graffiti Project , an online arts collective on a mission to archive images of bathroom graffiti from all over the world.
Graffiti has commonly and long appeared on posters, in particular on posters depicting persons. Most frequently such persons acquire decoration in the form of beards or horns, now usually added with water-resistant felt-tip pens. Such graffiti frequently appears during election campaigns. Though regarded as a form of vandalism, this graffiti gains some degree of acceptance, partially because of its merry appearance, and perhaps due to the temporary nature of electioneering. The alternative of tearing-down or obliterating such posters seems less witty. An example of this is Chicago-based sticker and poster artist, Melt.
Sometimes writing graffiti, psychologically, marks the successful completion of a difficult or distant challenge. For instance "Kilroy was here", leaving one's name at the top of K2, leaving a "human" mark in microscopic nanotubes or non-functional messages on integrated circuits. If the object or site of the challenge does not provide a surface suitable for inscribing challenge graffiti, humans sometimes fall back on other marking techniques, such as, for example, putting a bicycle lock around the object.
Drunk-shamers sometimes apply graffiti to drunk people sleeping off their inebriation. Such graffiti generally has an offensive and obscene nature and can take the form of writings all over the body or of shaving messages into body hair.
Sometimes writing graffiti becomes a purely symbolic act, a process of marking something knowing that nobody will ever see that thing again. The Voyager messages sent into space suggest one example. Other examples involve markings left by the makers of an object which will eventually become obscured or forgotten, such as the signatures of the engineers who assembled an electron microscope scratched onto a lead plate which cushions the heavy steel column on its base, or logos etched into computer microchips.
Tree graffiti gets painted or carved on trees, most frequently scratched into the tree's bark as expressions of people in love. During the 19th and 20th centuries, Basque shepherds in Nevada, Arizona, Colorado and California expressed their loneliness by carving Basque and Spanish texts or drawing women on aspens they found in their way.
Compare Chatham Islands dendroglyphs as tree-art. The United States Forest Service has lately recognized some carvings as valuable historic artifacts and studies how to conserve them against nature, logging and vandalism. A single scratch on a trunk might not harm a tree. Over time, the bark generates scar tissue that makes the scratch more visible. The wound might become critical if it totally cuts the sap flow. (The sap layer lurks just under the bark.) Ring barking, a scratch or gouge removing bark that forms a ring around the trunk, can kill the upper parts of the tree. Artists can also make tree graffiti, like other graffiti, by painting on a tree. However, in contradistinction to the case of carvings, botanists have not studied the effects of paint graffiti on tree health.
Sometimes coniferes are sprayed by their owners before Christmas, in order to prevent their illegal flling and use as Christmas tree.
Man-made Crop circles
Man-made crop circles or "field graffiti" constitute another form of vandalism, although not exactly within the modern definition of graffiti. However, some similarities exist: makers of crop circles generally operate at night and/or in remote areas to avoid detection/detention. The practice classifies as illegal if its practitioners trespass on private land.
Rarely seen by the travelling public, aircraft graffiti is very common and almost every commercial airliner is tagged in some way, more often than not written in the dirt or grease covering the aircraft. Although these messages typically appear in the cargo hold, they appear in every area where the ground crew works.
Typically, the graffiti takes jabs at employees at other airports, supervisors, or airline management, and is usually intended to be humorous rather than offensive. During labour disputes, pro-union and anti-management graffiti is also common.
Graffiti is often seen written in the dirt on road vehicles such as busses and trucks. (In the UK) this graffiti often refers to football, but there are some other common themes. One commonly seen line is "I wish my wife was this dirty", to which someone else invariably replies in kind "She is".