QUOTE(rosfrog @ Jan 21 2007, 01:01 PM)

If the bridge is hard enough and of good enough quality, the string won't cut in. Some luthiers put a piece of parchment on the e string part of the bridge to stop this happening too.
It is true a better quality bridge will increase its longetivity and the parchment is a great bonus, but ALL of them eventually end up with the E-string cutting in, albeit perhaps over a decade rather than just a few months.
It's impossible to avoid this process enitrely because metal will easily cut through wood. When you play you are putting pressure on the string, which in turn exerts increased downward force on the bridge - hence the string gradually cuts into the bridge. Given enough time, even the A-string will go the same way.
QUOTE(petrat @ Jan 21 2007, 10:41 AM)

My late father used to make stringed instruments as a hobby and always used to set a small wedge of blackwood into the E string slot when fitting violin bridges. I believe that it is possible to buy bridges like this now.
I've seen one or two bridges like this, but, I'm not sure what effect it has on the resonance of the bridge in general. Two woods of very different densities and hardness (although only a tiny piece) may possibly create tonal changes (physics coming in here!). I can't say for certain because I've never played a violin that's had a bridge with the blackwood insert. It would certainly be an interesting experiment though.