Can You Compost Envelopes?

Yes, envelopes can be used as compost ingredients. Envelopes would be considered brown compost matter (source of carbon).

Make sure the envelopes are shredded into smaller pieces before they are buried into the compost heap. Some envelopes, especially if they are junk mail, may contain small plastic windows on the side. The plastic should be removed as they don’t break down in the compost.

Reference: https://composting.ces.ncsu.edu/2017/03/over-100-items-can-be-composted-at-home/

Envelope Compost