In the 1950′s there were dozens of ballpoint models, and nearly every one took a different cartridge. In 1953 Paul Fisher invented the “Universal Refill” which could be used in most pens. It was a good seller, since stationery store owners could reduce their stock of assorted refills.
Not content, Paul continued to work on making a better refill. After much experimentation he perfected a refill using thixotropic ink-semisolid until the shearing action of the rolling ball liquefied it-that would flow only when needed. The cartridge was pressurized with nitrogen so that it didn’t rely on gravity to make it work. It was dependable in freezing cold and desert heat. It could also write underwater and upside down. The trick was to have the ink flow when you wanted it to, and not to flow the rest of the time, a problem Fisher solved.
Compact, convenient, and easy to travel with, people love Fisher Space Pens. We carry several varieties, including the Bullet pens, the Classic 400 Series, and the popular Trekker pens. Come into Maiden Lane to see our selection.