Labels & Addresses 1.6.9
Just in time for your holiday card production line, BeLight Software has released Labels & Addresses 1.6.9 with support for OS X 10.10 Yosemite. The label and envelope printing app also improves performance when working with large address lists, adds the capability to re-read data into a document quickly when information in associated files is modified, fixes the occasional crash associated with editing address panels, and addresses an issue with importing data from Apple’s Numbers app. Normally $49.95, Labels & Addresses is priced at $14.95 for a limited time during the holidays from the BeLight Web site and the Mac App Store. ($49.95 new, free update, 47.6 MB, release notes, 10.5+)
This software isn’t really designed for quick one-off envelope printing (or even doing a couple); it seems more designed for printing a lot of labels/envelopes from your address book.
There was a program in the past that worked great for one-off envelope printing (or several), including inserting the bar code above/below the address. It didn’t require any link to the Address Book. Unfortunately, it was never updated to run with OX10.
Yes, that's true. Labels & Addresses is more for bulk printing. You might look at Ambrosia Software's Easy Envelopes for one-offs (haven't used it personally).
http://www.ambrosiasw.com/utilities/easyenvelopes-mac/
I use Easy Envelopes for one-off printing. It works a treat!