Vincent Connare has only used Comic Sans once in the 20 years since he designed it to be the voice of a cartoon dog. "I was trying to switch my broadband to Sky a couple of years ago and they failed to send me a modem so I had no internet for a month," he says.
"I wrote a letter and thought it was appropriate to take the piss and say, I'm so angry at you I don't really care about manners and I'm going to use this typeface."
The jolly creation has been used incongruously - sarcastically or otherwise - for as long as it has existed. Primary schools, village halls and aunties love it for its engaging, informal style, but it is also a subject of ridicule. Dave Gibbons, the renowned comic book creator, whose work inspired Connare, once called it "a real mess", adding: "I think it's a particularly ugly letter form." There is even a campaign to ban it.
Better-humoured designers celebrate the font for its clear identity and popular success. Tonight, an exhibition of posters by top designers opens in London to mark 20 years of Comic Sans.
Chris Flack, a designer from New Zealand based in Britain, curated the exhibition to raise money for Cancer Research when he noticed there were no plans to mark the anniversary.
Connare himself has supplied a poster ? a photo of his cat with a caption, written in a Comic Sans variant: "Do I look like Helvetica Neue?!" Helvetica is the antithesis of Comic Sans: neutral, elegant and loved by design buffs ? but not fun. "I used it to sarcastically say, I'm a cat and I don't talk in Helvetica," Connare explains.
The gag recalls the typeface's original function. In 1993, Bill Gates hired Connare as a "typographic engineer", partly to jazz up Microsoft's drop-down menu before the launch of Windows 95. To help lead users into the unfamiliar world of home computing, the system came with "Microsoft Bob". Bob's dog, Rover, popped up with tips in speech bubbles, but he was due to speak in Times New Roman.
"I said it would be better in the style of comics or cartoons in newspapers, so they asked me to do something," says Connare, who is from Boston but has lived in Britain since 1999. Now 53, he works for a font design studio in Brixton, south London. "I drew up Comic Sans in about three days. I thought it would go into a pile and get forgotten about."
Consumers had other ideas, while businesses applied the typeface to signage and to bring a sense of cringey fun to corporate literature. But it was never cool and the backlash came quickly. In 1999, two American designers launched the Ban Comic Sans campaign. Gibbons, whose work with Alan Moore in the Watchmen comics had inspired Connare, took aim in 2009.
Connare, who is also responsible for the Ministry of Sound logo and a new, award-winning font for Nokia, says he has never been bothered by the criticism, putting it down to design snobbery. He is amused to learn about an unlikely preference for Comic Sans in the House of Lords. Earlier this month, Lord Steel, the Lib Dem peer, filed an opinion piece to this newspaper about the ongoing crisis in Israel. An attached Microsoft Word document called "Time to talk to Hamas" opened to reveal 900 words about a subject that could hardly be more serious. He had written it Comic Sans.
Lord Steel replies with bemusement to a polite inquiry about his use of the typeface. "It is my preferred font, just because I like it, but know nothing about it, sorry!" But does he think its comic-ness changes the reader's perception of what is written? "I have used it since I became computer literate late in 2003," he replies, again in Comic Sans. "The comic title did not bother me, I just liked it and no one has ever commented."
"That's what everybody says - they just like it," Connare says. "They don't know why but they're not designers but regular people. It's like when people talk about modern art. I went to the Rothko exhibition recently and a man looked at his black painting and said, 'I could have done that'. Yes, but you didn't!"
Simon Garfield, author of a new book on fonts, Just My Type, said: "There was an age when fonts were things in the hands of designers and professionals, but the arrival of PCs and laptops changed all that. Software allows people to instill their emotions into type and Comic Sans has an approachability - it looks as if people have written it themselves.
"The trouble is that it is good for use only in a limited number of ways. It is not appropriate for the side of ambulances or the font that the BBC uses to promote its composers of the year. There is an element of typographical snobbery about all this, but you can't get away from the fact it has just become too popular." But Mr Connare said: "I don't think Comic Sans is 'too popular'. It will be when people stop using it.
"Until then put it on everything from a loaf of bread in Provence to a beach towel on Bondi Beach."
My worst fonts, by Simon Garfield
Reminiscent of something Fred Flintsone might carve into prehistoric rock, or more recognisably, what Disney used for its most successful cartoon animation of all time, The Lion King. Invented by a German typographer, Rudolf Koch, in 1923, it is now considered a "Theme Park" font, more comfortable on rides at Alton Towers than on the page.
"Souvenir of what, I would like to know?" asks Peter Guy, a book designer for the Folio Society. "A souvenir of every ghastly mistake ever made in type design gathered together - with a few never thought of before - into one execrable mish-mash." Appeared on Bee Gees Albums and occasionally in Playboy.
Avatar may have cost more to make than any other film in history, but its use of font was far less extravagant, having been available free on every desktop PC for some time. Avatar's director, James Cameron, was even pictured in a T-shirt asserting @Papyrus 4 Ever!"
First made available in America in 1942, this font was used by American propagandists to persuade country folk to "bathe with a friend" or "dig for victory" - Britain's Ministry of Agriculture showed far less extravagance. Also the type face used to introduce the soap Neighbours to the world in 1985.