British Registered Design lozenges
A list of Registered Designs which are signified by one of two lozenges (illustrated below), which appear either moulded into pressed glass, or etched (with acid or diamond-point), gilded or enamelled on hand-blown glass. Contains designs registered in Britain by major glass manufacturers, importers, wholesalers and retailers, from 1842 to 1883
First, check to see where the letters and numbers occur in the lozenge on your item, and decide which of the above two types of lozenge applies. Use the key to Year and Month code letters (next section) to decipher the full date of registration, then click on one of the boxes below to take you to the year-range containing the date of your Registered Design
keys to Year and Month code letters
If the lozenge is hard to decipher (often the impression is unclear), the "parcel" number (the last column on the following pages) may help confirm whether or not you have the right Registration.
The "class" number for glass items will always be "III"
For the first lozenge, R may be used for the month mark from 1st to 19th September, 1857, and K used for December 1860
For the second lozenge, from 1st to 6th March 1878, G was used for the month and W for the year