In our series Sticks & Stones, we take a deep dive into medium. Each installment features one of art history’s most significant materials—its history, evolution, and unusual uses. (See past installments.)

The distinctive look of artwork made with spray paint has become synonymous with rebellion and counterculture. On the walls and train cars of nearly every major city of the world, you will find vividly colored murals and graffiti tags. Some are hastily sprayed, others painstakingly designed and crafted—but all share the same sense of subversive verve and youthful energy.

Considering the symbol it has become, it’s surprising that the spray can has the most suburban and domestic of origins. The original concept came from Ed and Betty Seymour, of northern Illinois. Ed had been tinkering to try and develop an easy way to apply aluminum coatings to radiators, when his wife suggested using an aerosol, similar to what was used in (newly invented) hairspray. When the Seymour’s paint company, Sycamore, released their first ‘spray paint’ canister in 1949, it was an instant success.

The even finish and quick dry-time made it popular with its intended commercial audience—industrial manufacturers and handymen—but it was the compact, easy-to-conceal size and speedy application that gave it traction with an unintended audience. The new media was quickly taken up by protesters and vandals, who adopted the imprecise, messy look of spray painted lettering as a form of visual branding, expressing their grievances with society.

Early graffiti often took the form of ‘tagging’ objects in public spaces with a name or pseudonym. Early proponents of spray paint tagging included the Philadelphia-based ‘Cornbread,’ and New York-based ‘Julio 204.’ By the late 1960s, the colorful scrawls of tags, messages, and simple cartoons had become a common sight on the streets of America’s cities. Graffiti’s rise to pop culture relevance happened in tandem with the hip-hop movement taking place in New York’s downtown scene, with both groups seeking to find work outside of mainstream commercialism and censorship. By the 1970s, spray paint was the vernacular of society’s discontents: street art became a public platform for political commentary on issues like class division, homophobia, and racism.

The first major street artist to be credited with the use of stencils was Blek le Rat, a Parisian graffitist working in the early 1980s. His work has been referenced by many since, notably Banksy; the frequent motif of rats in the latter’s work is thought to be a reference to Blek le Rat. The addition of stencils to the street artist’s tool kit enabled the rendering of sharp lines and precise shapes, opening the door to more complex, detailed imagery. Graffiti is illegal in most states and countries, so any spray painting must be executed speedily and discreetly. Stencils allowed street artists to take as much time as they desired to craft their images in private, before spraying them onto their intended surface.

Despite major efforts from politicians and law enforcement to keep graffiti off the streets, the underground art form made a leap into the mainstream art world in the early 1980s, with the work of Keith Haring and his contemporaries, like Jean-Michel Basquiat and Kenny Scharf. Haring had become well-known for his upbeat and joyful cartoon style, with its easily recognisable motifs like the ‘radiant baby’ and the ‘barking dog.’ His work addressed pertinent issues and ideas of the 80s, with particular focus on the AIDS epidemic, and the push for mainstream acceptance of homosexuality. Haring had his first few gallery shows in 1981, going on to create major public artworks, including a mural on the Berlin wall, rocketing both himself and graffiti style to fame.

Today, cities around the world have street art festivals to showcase local talent and beautify the urban environment, and the work of graffiti artists is shown in many major museums. Beyond being a widely admired and loved form of creative expression, it’s a common gateway into creating fine art. The media exudes a democratic, unfussy attitude that makes it welcoming to everyone, and aspiring artists often feel less intimidated picking up a spray can than an oil palette. The graffiti aesthetic, which reached its peak in the 1980s, has filtered back into contemporary art, from the superflat paintings of Takashi Murakami to the declamatory public slogans of Jenny Holzer. Much like Ed and Betty Seymour with their first spray cans, the earliest graffiti taggers and street artists could not possibly have anticipated the impact that their contributions would have on culture at large.