[pianotech] new ivory

[Ed Foote]

Greetings,
    A customer is considering having her keyboard restored, which in 
this case, means a new set of ivory or something other than plastic.  I 
heard, several years ago, of alternatives such as walrus tusk, certain 
cow-bone, etc.  being introduced to the piano market.  What, if anybody 
cares and knows to tell, is the performance of these alternatives?  
This is for a piano teacher, the keys will be used a lot.
thanks,

Ed Foote RPT
http://www.uk-piano.org/edfoote/index.html