Merge to Envelopes
Available only in the Google Docs Add-on
Here are the steps required to merge into envelops and print them off
1. Change your document template page size to the size of your Envelope
Google doesn't allow you to do this, so you need to install the 'Page Sizer' add-on and set the size as shown in the image below:
2. Then insert your merge fields as usual and merge to letters
3. You should get a document with an envelope for each page as shown below.
4. Insert your envelopes into the printer and print the merged document