It is common for draftsmen to sprinkle SCUMEX (powdered rubber eraser) on tracings prior to doing any drawing on it.

It is common for draftsmen to sprinkle SCUMEX (powdered rubber
eraser) on tracings prior to doing any drawing on it. This reduces
smearing of the pencil marks and such and results in a cleaner
tracing.

At a former employers we had replaced the Scumex at one draftsmans
desk with dried parmesian cheese. It looked about the same. It was
extremely interesting watching him draw for a while and then begin
to smell the paper. Took the poor dude almost 10 minutes to guess
that he had been gigged!

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