"Great for old fashioned preserving"
People I gift preserves to often comment on how nice it is to have the 'proper' old fashioned waxed discs for protecting the tops of the preserves from mould and bacteria. Even though I use jars that have lids, mine are re-used so I find the cellophane circles useful to put on top beneath the lids. This does two things: Protects the preserve in the case of a lid starting to deteriorate and also helps ensure a tight seal. The rubber bands get used to hold on decorative cloth or paper circles, which I then tie round with ribbon. It gives a very satisfying result.