Brown 4H Wolff's Ferronprint grey lead pencil used by engineers working on CSIRAC. This pencil may well have been used for drawings and flow charts during the period that CSIRAC was at the University of Melbourne.

Pencils were used sometimes in preference to fountain pens; the use of ball-point pens was only then becoming commonplace.

The following has been edited from - accessed 10 December 2008.
Drafting pencils are made in a number of grades, ranging from hard to soft. Generally, hard pencils draw light lines; soft pencils draw darker and wider lines. The hardest standard grade for drafting/drawing pencils is 9H. The softest pencil is grade 6B. In general, a 4H pencil is used for light layout lines and guide lines that are easy to erase. A sharp H pencil is used for thin dark lines (dimension and extension lines, template work, and lettering). A blunted F pencil is used for thick/dark object lines for walls and borders.

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