I've been happily shredding envelopes together with junk mail and other
superfluous letters and adding them to my compost. I read recently that
certain guests of Her Majesty were employed opening undeliverd letters and
extracting the little plastic address windows before sending them (the paper
envelopes that is, not the plastic bits) to be recycled.

Anyone know what the plastic windows are made of and will they compost?

Trefor