At Previously, we write in pencil.  And no pencil has the incredible legacy of our choice of pencil, the Blackwing.  Once described as "the Gullwing Coupe of the pencil world", the Blackwing was a 20th century icon, making devotees of Steinbeck, Sondheim, Ezkstein, Stravinsky and even Mad Men's Paul Kinsey.  PU's Theo de Monchy shared their remarkable story with Idealog here.