How to set custom paper size? – Woo Invoice

    Adding different paper sizes is only available in the premium version of the plugin. Available paper sizes are A3, A4, A5, Letter, or any custom dimension. 

    1. Go to the Woo Invoice > Settings from your WordPress Dashboard.
    2. Click on the Invoice tab.
    3. Into Invoice Template section you will find an option to select your Paper Size. If you need a custom dimension then select the option Custom Paper size and enter width and height in millimeter (mm).