Thunderbird only has the ability to print emails or an address book. Thunderbird is not the correct software for wanting to perform something like printing labels. You would need to use MSOffice package or OpenOffice.org (free) see link: https://www.openoffice.org/ I know you can use OpenOffice.org Writer program to create labels. Using OpenOffice.org Base you can select to connect to an existing database and select Thunderbird Address Book. In thunderbird, Export an address book as .csv file to a suitable folder for the purpose. In openoffice base connect to an existing database - text - next choose path to folder where tb address book .csv is stored. select comma separated - next Register database click on finish selected folder will open so you can save the new database.odb file. After saving to a suitable location, you can then use OpenOffice.org Writer. File > New > Labels select the saved filename.odb database. See image below as guide.

Thanks for that. I thought that would be the case. Much appreciated.