[Spits] Rubber Seal Residue

[Matthew Milkevitch]

Hello Listers:
First of all, thanks to everyone who informed me of what tire
pressures they are running.  
Secondly...I would like to solict some comments
on the following.  Some time ago, I replaced the outer window seals on my
'77.  These are the rubber seals that "scrape" the outside of the drivers and
passengers windows.  
Since their installation, I've noticed that if I clean
these seals, a blackish residue is left on my cleaning rag...and also on the
body work of the car.  
Has anyone else observed this?  Is there any way to
clean this residue complete off/out of the seal?
Thanks for your comments...
Matt Milkevitch
'77 Spitfire