Harrison Dummy Stamps of King George V
Harrison won the 1910 British low-value definitive stamp tender, despite only previously having printed one 1866 revenue stamp for Mauritius. Development trials perfected production techniques for sheets, while booklets and coils for vending and affixing resulted in test stamps; publicity labels promoted their new skills.
Letterpress was initially employed, with its intaglio capability not utilised in this reign, despite producing publicity labels. Photogravure was adopted by 1921 - one of the first security printers anywhere to do so - and this proved an excellent decision. In 1923 Harrison called on expertise from Dutch company NRM to train staff in making cylinders and to print by photogravure. Dummy stamps were printed in Holland by Harrison staff, while NRM later helped to print some values for its Egyptian photogravure contract in 1923.
Harrison's expertise in photogravure stamp production grew and this guaranteed worldwide contracts. They went on to print most British stamps this way until eventually taken-over by its arch-rivals De La Rue in 1997.