Royal Mail PPI Stamps: Which Labels Should You Use? - Label Planet Royal Mail PPI Stamps: Which Labels Should You Use? prev next Design 1 measures 14mm x 54mm - you could use LP27/63 (29.6mm x 63.5mm) Design 2 measures 30mm x 58mm - you could use LP18/63 (46.6mm x 63.5mm) Design 3 measures 22mm x 80mm - you could use LP16/99 (34mm x 99.1mm) Design 4 measures 26mm x 93mm - you could use LP16/99 (34mm x 99.1mm)