The US Postal Service has approved the first two-way postage indicia for reusable envelopes (great, they are going greener).

EcoEnvelopes will make the envelopes for them.

You will be able to use one-printed indicia – markings showing that postage has been paid – for both outgoing and reply postage on an envelope.

These are available to organizations using approved reusable envelopes along with a bulk rate permit using an Intelligent Mail Barcode.