Self-adhesive laser labels for your printer (inkjet or laser) or copier.
Also transport labels for DHL, etc.
12 transport labels per A4 sheet, with a receipt section. Approximately 99 x 42mm.
Templates are available online.
Google keywords like "templates" and "sheets labels A4" and perhaps include a number corresponding to your label count per sheet. For example: "templates labels a4 sheet 21."