Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Hollmike-at-aol-dot-com> Hi, The transparency sheets are very likely mylar. Now there are some translucent sheet protecters that are polypropylene. Mike > > Suggest you check what material it is made of and look at dielectic loss of > it before spending too much time, it could be lossey > Best > TEd L in NZ