Custom Label Size
How do I create my own custom label size?
From the Google Docs Add-on Only
Click Add-ons > Avery Label Merge > Custom Label Size.
This will open the Custom Label Size dialog box.
Enter values for Label Width and Label Height.
You can change the units to Inches, Millimeters, etc from the Units in drop-down and page size to Letter, A4, etc from the Printer Page Size drop-down.
Further customization is possible by changing the Page Margins (i.e. the space between your labels and the edge of the page) and Spacing Between Labels.
Click Save to apply changes.
Once a custom label size is defined, the label template box changes to the defined size.
The Label / Envelope field in the Avery Label Merge sidebar will also change to Custom Label.