The company keeps pens that have become collectors' items
Two hundred workers have marked the 120th anniversary of Sussex-based Parker Pens by burying a time capsule.
Geoffrey Parker, the great-grandson of the company's founder, also planted an oak tree outside the firm's factory.
The company's roots are in America, but it has had an operation in Newhaven since the 1940s.
Mr Parker said his great-grandfather "felt it was very simple to succeed in business - make a better product and people will buy it".
Employee Peter Easton, said the company had "always been a family-orientated business".
He said the factory had seen "lots of generations of families" working there, and that people had connections with the firm "all around the area".
The company also keeps pens that have become collectors' items.
Heritage director David Ruderman said an Aztec pen had sold in the past decade for more than £50,000.
He said: "I consider myself very lucky to be the guardian of all these goodies."