This PDF instructs you on how to build a Rough and Ready Chair. The project by designer Tord Boontje is an early example of open-source design. The chair can be made from found wood, a blanket and some string, tape or wire. 

'The Rough and Ready collection  is made from materials which have been salvaged or are common place and cheap. The pieces, as their title suggests, appear rough and ready. They have a sense of incompleteness, a feeling that things might change. They are utilitarian works, which acknowledge the beauty of imperfection and offers an alternative to slick objects.'

Studio Tord Boontje | 1998 

Find out more about the project here.