Theodor Kovacs altered the course of fountain pen history when he designed the differential piston filling mechanism. Prior to his creation, fountain pens were known to have smaller ink capacities and were somewhat cumbersome to use. While not the first piston mechanism to ever grace a fountain pen, it was perhaps one of the best. Patented sometime around 1925, Mr. Kovacs entered into a partnership to see his design put into production. When that relationship fell apart due to financial hardship, he sold his patents to Günther Wagner in 1927. The company would re-patent them under their own name in 1929. Later that year, Günther Wagner introduced its first writing instrument based on the differential piston filling mechanism, the transparent Pelikan fountain pen, initially provided without a model number. Next year will mark the 90th anniversary of that original release. To commemorate such a milestone in the company’s history, Pelikan is set to make available the Herzstück 1929 Limited Edition anticipated sometime around the end of March 2019.