Woody Harrelson is helping to save the world's trees by launching his own eco-friendly line of paper. The Cheers star has invested in the Prairie Pulp & Paper Inc. company, which uses a wheat-straw waste and wood fibre alternative to tree pulp to make paper. The line of conservationist stationery has been 15 years in the making, and Harrelson claims that by replacing two packs of traditional paper with his product, users will save one tree. Harrelson, a long-time environmentalist, says the new paper is "going to be great for our future". The line will be sold in the U.S. through retailer Staples.