You don't intend to mark the entire distance of the depth of the tails do you?
You'd be stuck with cut-in lines between the tails, use a pencil for that line.
But I think it would be better to use the kind of gauge that uses a wheel cutter
instead of a pin, which would do some shredding of the wood. My suggestion
is buy this one:
http://www.leevalley.com/wood/page.a...33&cat=1,42936
or their 3-in-1, don't make one.

--
Alex - "newbie_neander" woodworker
cravdraa_at-yahoo_dot-com
not my site: http://www.e-sword.net/