Red/Blue Pencils

Pencil Talk has reviewed a few obscure bicolored (red and blue) pencils which, in and of themselves, are fairly rare these days. I love the idea of having a double-ended pencil with red and blue but does anyone know the original purpose for using these? (via pencil talk)

Read the detailed tale of the revival of the Blackwing pencil from the end of the original production run to the new versions issued by Palomino. Oh, how we can be so passionate about just the right writing instrument! (via Fortune from May. 19, 2011)