For those who can get to Ballarat (Vic), then the place for ebony star is Ballarat Joinery Supplies. They bought in a sheet for me no wurries. Phone (03) 5333 3008, website
www.ballaratjoinerysupplies.com.au
I would suggest that most joinery supply outlets would be able to get ebony star for you. The '50' is the one to get, less surface area touching the teflon. Note, Ballarat Engineering Plastics can supply teflon in various thicknesses, including one with a backing that allows the stuff to be glued in place. Not cheap, but worth it!
Regards
Chris