A year ago the talented portraitist and filmmaker Chris Floyd faced a fleeting quiet moment, but at the same time his Twitter following was exploding. So, resourcefully, he decided to combine the two. After extending an open invitation to his studio, he began to meet and then photograph his Twitter connections. The result became One Hundred and Forty Characters, a collection of 140 portraits that will be on display at Host in London from 3 to 17 November.

If you missed the cut, don't despair. We've asked Floyd to tailor his concept for Wallpaper's 500,000 Twitter followers. He's agreed to snap those who visit our Tweet Life pop-up studio at this year's Multiplied Contemporary Editions Fair at Christie's, between 14 and 17 October. The sitting is free, and you can purchase your portrait for £10 at the fair. Floyd will then select 140 photographs to appear on Wallpaper.com at the end of the show.

We caught up with Floyd to learn more about this snowballing project.

You say that you initiated One Hundred and Forty Characters during a lull, a time when inspiration was lacking. What inspired the project?

That was July 2010. It had been a quiet few weeks. Around four years ago I bought my first digital camera, and within a year I was almost exclusively shooting digital. Part of the joy of using film was that it involved lots of contact with human beings in lots of places - film labs, printers, magazines, agencies... But the price you pay for the advantages of digital is you disconnect yourself from other people. Economically it's been a big bonus, but in terms of my social life, it's really suffered. I realised I just didn't see anyone any more. I don't use Facebook but I did join Twitter, and I found I was using that to talk to people. And soon I realised I connected with them more frequently and intimately than with people I've known for 20 years.

So you decided to meet up with them personally?

I didn't want to have to go to 140 addresses, so I invited them to my studio. Also, I wanted all the photos to be uniform, shot in the same place. I killed several birds with one stone, really. I filled a lull in my work and had a meaty project to do. And the funny thing is, all the people in the project who are freelance, they get unbelievably lonely, so they thought it was brilliant.

At what point did you realise there was really something special there - that it wasn't just for you?

Quite early on. It really evolved very quickly. Within two or three days I knew I was on to something. People taking part went away after being photographed and tweeted about it, then their followers were suddenly interested.

What - or who - were the highlights?

I wanted to use the white space in the frame to bring together people who had not met each other. One shot had about 15 in it. They were all brought in by Dr Sue Black, the head of computer science at the University of London (and a follower of mine). I sent her a message and asked if she would take part. And she recruited some people she'd been talking to on Twitter. There was a whole mix: a photographer, taxi driver, civil servant, the woman who heads up air traffic control at Heathrow... they all came that day and none of them had met. And it felt great because I served as a catalyst for that.

Do you keep in touch personally with any of your followers?

Yeah, quite a few. I'd say on a regular basis probably 25. I recently worked on a film, and nearly everyone involved - the editor, the sound engineer, the cinematographer - I'd found through Twitter.

So you could say Twitter has literally transformed your way of working?

Yes. It's sort of like wandering around in a vegetable patch and all of a sudden you stumble onto a juicy cabbage.

You are teaming up with Wallpaper* for our Tweet Life project at the Multiplied Contemporary Editions Fair. How are you going to distinguish this new project from One Hundred and Forty Characters?

I like the idea that this sort of project is fundamentally about social tribes. One Hundred and Forty Characters is about my tribe. At Christie's I'll be shooting the Wallpaper* tribe. I have an inclination to shoot just faces. And I might do it in colour. I won't really know until I get there.

Based on your previous experience, what sorts of people do you expect to turn up?

Yesterday Wallpaper* tweeted about our collaboration and within a half hour I'd got about 40 new followers. The response was totally global, people from Gothenburg, Buenos Aires... they all have distinctly non-Anglo Saxon names. So the crowd will be diverse, clearly. Twitter is a world without borders, isn't it?