Lucy glared at me from a young woman’s bicep, her mouth picked out in a crabby zig-zag of dark-blue ink on pale skin. Yes, that Lucy, the-doctor-is-in, Peanuts Lucy. On the woman’s right arm Pig Pen hovered in a cloud of inky blue grime among a gallery of other stick-and-pokes.

The girl with the Lucy and Pig Pen tattoos was among the crowd at the Melbourne Art Book Fair – you can imagine the scene when you put “Melbourne”, “art” and “book” in the same sentence and turn it loose in the Great Hall of the National Gallery of Victoria for a weekend. How to put it? The Venn diagram of people who went to the Art Book Fair and the Grand Prix – which was on at the same time just down the road – is a nearly empty set.

“I like to think Charles M Schulz would approve,” she said (I doubt it – I imagine he was a Minnesotan of the old school, much keener on the Little Red-Haired Girl than the Girl With the Dragon Tattoo), and I don’t know what the Estate of Charles M Schulz would make of this apparent violation of their copyright – but can you license a cartoon character for reproduction and publication on a person’s skin?

Tattoos are now so ubiquitous as to be unremarkable. The real question is how to make your tattoo worth noticing without going full body Yakuza.

One bid was spotted browsing at the Art Book Fair not long after the Girl With the Peanuts Tattoo. On her left forearm: a Keith Haring mini-canvas of a love heart in red ink held up by a pair of wiggling blue Haring stick-people inside a neat border.

Keith Haring was the New York-based 1980s artist who took graffiti off South Bronx subway cars and put it onto the gallery walls of the Lower East Side.

Then he took it off the gallery walls to reach a wider audience via the Pop Shop – on T-shirts, postcards and other merch. Haring died in 1990; Pop Shop earnings now go to support children affected by AIDS.

One of his works, done on a visit to Melbourne in 1984, is still visible on the wall of Collingwood tech in Johnston Street.

Whatever you think about the tattoo appropriation of Haring’s appropriated graffiti art or the violation of Charles Schultz’s copyright, one thing is for sure: the art in Melbourne isn’t just in the books at the Art Book Fair or on the walls of the NGV. It’s walking around, too – on people’s skin.