My thinking tool, along with a ream of 80gsm blank white printer paper. As well as being ubiquitous, reliable and cheap, you can also vary the line weight it p

My thinking tool, along with a ream of 80gsm blank white printer paper. As well as being ubiquitous, reliable and cheap, you can also vary the line weight it produces with pressure. This makes it great for sketches and diagrams, as well as straight writing.