In article .com,
"Stache" wrote:

Michael Horowitz wrote:
I want to mark sheetmetal for bending.
Can't use a scribe because I'll weaken the metal.
Magic Marker is too thick.
Pencil doesn't show.
What do you use? - Mike

From an old gray hair tin bender, use a #2 pencil it will show. To get
the proper bend allowance and set back lilne I use a #2 pencil some
will use a Graphite pencil, but it is very ligh. I would suggest
wiping the sheetmetal surface clean then the pencil will be more clear.

Stache

NOT ON ALUMINUM! The graphite from the #2 pencil will galvanically
corrode aluminum. Use a Sharpie and clean with either lacquer thinner or
denatured alcohol after you are done.