Craven with his wife Christine set up a company to produce the lamps, naming it Crestworth. Operating from small buildings on an industrial estate in Poole, Dorset, Crestworth has supplied the world with lamps since 1963, changing its name to Mathmos in 1992. They were a commercial success through the 1960s and early 1970s, and became a symbol of psychedelia. Craven said, "If you buy my lamp, you won't need drugs... I think it will always be popular. It is like the cycle of life. It grows, breaks up, falls down and then starts all over again." In the late 1970s fashions moved on and lava lamps fell out of fashion. The Walkers kept the company going throughout the 1980s but in a much smaller way.
In the early 1990s, a young couple began manufacturing and selling them successfully. Cressida Granger and David Mulley approached Craven and took over running the company and renamed it Mathmos in 1992. Initially they were in partnership with Edward and Christine Craven Walker and the company was called Crestworth Trading Ltd. Over a period of years they bought out the Walkers bit by bit.