The NGO accused the company of destroying "huge" tracts of forest in Lapland - among Europe’s last remaining ancient forests - to make paper for well-known European magazines.
Forty protesters raided the company’s paper mill in the Finnish town of Kemi to prevent timber deliveries.
Greenpeace says its research shows the company uses timber from ancient forests to make magazine paper. It also supplies all leading envelope producers.
"Unless magazine publishers in the UK like IPC and EMAP want to be associated with the destruction of 1,000-year-old forests, they should be putting pressure on suppliers to ensure they are not sourcing fibre from this area of Finland," said Greenpeace campaigner Ben Ayliffe.
"The best way to guarantee your paper is not coming from Europe’s last remaining ancient forests is to maximise recycled content and only use virgin fibre certified by the Forest Stewardship Council."