Ipex, held every four years in the UK, has traditionally been the second biggest global printing exhibition after drupa, a quadrennial event in Germany.   However, the latest Ipex at ExCel, a London exhibition site, in late March confirmed that it has been drastically affected by the trend among major companies, not just in printing but in many other sectors, to shun large exhibitions as a means of promoting their products.     In the printing supply chain, the leading players, including the...