Cellophane is made from cellulose and is therefore biodegradable - you can add it to your compost or put with other biodegradable waste, like garden waste.

However: beware! Most packaging that is called or looks like cellophane is in fact polypropylene, which does not biodegrade.

It is possible to buy envelopes with cellophane windows. Haven't yet found a supplier who can provide FSC certifed envelopes with cellophane windows - perhaps you can help?

Carrierbagshop sell cellophane bags, as do Packaging People and other suppliers.