As a giant cloud of volcanic ash blankets Europe, forcing countries to impose the biggest airspace closure since 9/11, it's business as usual at Art Cologne – at least behind the scenes. The installation and fitout of booths and visitor facilities is almost complete and galleries are beginning to install. In the Art Cologne office, however, staff must be thinking wistfully about the good old days when organising a fair was a relatively straightforward exercise. Over the past twelve months, art fair organisers have run into Swine flu, a global recession and now an Icelandic volcano spewing ash into Europe's air space.