The History of Rubber Stamps
(source:)
http://www.goldingcraft.com/rstamp.htm
Prior to the rubber stamp, there were metal printing stamps, usually made of brass. These preceded the rubber version by six to eight years. We remember them in the form of seals, used with wax to ensure the privacy of documents. The seals themselves were generally very elaborate. The word 'stamp' is used to refer to a marking device.
There is some confusion surrounding the production of the first rubberstamp. In America, Charles Goodyear discovered the process by which rubber is cured in 1844, while he was experimenting in his kitchen. He dropped a mixture of rubber and sulphur on to a hot stove and found that it was still flexible the next day. The process was dubbed vulcanisation after Vulcan, the Roman god of fire.
The birth of the rubber stamp was closely entwined with early dentistry. Vulcanised rubber, set in plaster moulds, was used to make cost-effective denture bases. Dentists had their own round vulcanisers, called 'dental pots', which would be used, eventually, to manufacture the first rubber stamps.
In 1866 James C. Woodruff started experimenting with a vulcaniser, trying to make some letter moulds. He asked his uncle, who was a dentist, for help and advice and after additional experiments with the 'dental pot', the first quality rubber stamps were created. Some of the rubber stamp companies formed in 1880 are still in business today.