Unlike most major manufacturers of the era, Parker largely stayed away from the lever fill mechanism.Although they did produce some examples of lever fillers, they prefered their own homegrown mechanisms.Supposedly this helps draw ink back into the pen when it wasn't in use.Parker used the Lucky Curve into the 1920s as a competitive market differentiator in a crowded pen market.During the 1920s and 1930s, this was the button fill mechanism, which used a button hidden behind a blind cap to compress the bar that the lever would have compressed.The Duofold, introduced around 1922, formed the top end of the Parker line through the 1920s.The fountain pen was available in Europe in the 17th century, and is shown by contemporary references.
The new pens were streamlined, with smooth, tapered ends. The highly transparent pale green first used is particularly delicate, though the later, brighter greens are also very difficult to find in their original state.
There is compelling evidence that the first working fountain pen was constructed and used during the Renaissance by artist and inventor Leonardo da Vinci.
Leonardo's journals contain drawings with cross-sections of what appears to be a reservoir pen that works by both gravity and capillary action.
Filling the reservoir with ink may be achieved manually, via the use of a Pasteur pipette (eyedropper) or syringe, or via an internal filling mechanism which creates suction (for example, through a piston mechanism) to transfer ink directly through the nib into the reservoir.
Some pens employ removable reservoirs in the form of pre-filled ink cartridges.