4D 3mm 4D 3mm use acrylic letters that have been laser cut using the finest quality acrylic. We the Perspex brand for the lettering which has many advantages as follows; Perspex®, Not Alternative 10-year Colour Guarantee UV Stabilised Easy to clean Excellent Chemical Resistance Weather Resistant The letters are stuck on the plate using industry standard transparent glue sheets which bond to the plate. The glue is very strong and jet wash friendly. Our reflective sheets are of the highest quality and have been tested under the latest British standard (BSAU 145e). Our shatter resistant acrylic, which is also tested under the same British standard, ensure you have plates that last you a lifetime. If you have opted for an import size (13X7, 12X6, 9X7) then the characters will be smaller than a normal number plate. Import sized plates have characters with 64mm height and 44m width as oppose to 79mm height and 50mm as standard. All road legal number plates require the manufacture name and postcode printed along with the British standard code along the bottom. These will be printed by default on your road legal plates.