You’ll often read in old descriptions of steel pens comments about a pen’s “action,” as in “An easy action” or “the action of this pen being similar to that of the quill.”
What is “action”? This 1853 ad for Rhoads & Sons spells it out. Action is a combination of the flex of the tines, i.e. the spread of the tips, and the spring in, or close to, the body of the nib.
This stiff action was seen as a cause of many problems, including hand fatigue, enervation of the wrist (probably carpel tunnel), and other issues.
Manufacturers attempted to solve this problem in different ways. Some made special pen holders with a rubber or spring end that allowed the pen to imitate having some flex. Others, like Rhoads, tried different materials beside the rigid steel being used at that time. The most extreme of these was probably the short-lived rubber pen nibs, made with Charles Goodyear’s newly invented vulcanized rubber.
One of the earliest solutions was to add slits and piercings, as Rhoads alluded to, to soften up the body of the pen. We saw the first three-slit pen advertised by Peregrine Williamson in Baltimore in 1808. Later, Gillott patented the three slit pen in England and claimed the pride of discovery.
In 1853, a stationer, inventor and pen maker in New York City, Myer Phineas was granted a patent for a new kind of pen with broad cuts made across the body of the pen. This removal of material allowed the body of the pen to flex and create that softer feel.
This idea looks a lot like a form we find in later pens called the Double Spring, like this Esterbrook 126.
We find the name “Double Spring” applied to pens quite early, but without a picture to go with it. For example, in this ad from 1838 for Charles Atwood’s pens, we find both a Double Spring as well as an Elastic Spring. But without images it’s not clear if Phineas just improved on a design the Esterbrook was also hearkening back to, or if the Esterbrook took its name from earlier styles but implemented a restrained version of Phineas’ design?
Eventually, a combination of slits, piercings, grinding and much thinner steel led to nibs with a softer action. These pens were perfected about the time that call for soft action began to decline. People were more used to steel pens and less familiar with quills, the writing styles, like copperplate, which called for this softness were being replaced by more monoline business penmanship styles that didn’t require so much flex of the tines.
Fountain pens were also become more affordable, and fountain pen nibs less and less displayed a soft action. Carbon paper made “manifold” and stiffer nibs much more popular. The smoothness of tipped fountain pen nibs also resulted in less hand cramping. By the 1930’s, flexible fountain pens were fairly unusual. Soft nibs continued to be made, and some are made today, but that softness was only half of the equation. They would still be considered as having “a stiff action” by the standards of the 19th-century.