Eduard Slavoljub Penkala was a prominent Croatian inventor and engineer with Polish-Dutch-Jewish roots, whose innovative ideas contributed significantly to the development of writing technology and aviation in the early 20th century. His work had a global impact and his name became recognisable far beyond the borders of his adopted homeland, Croatia.

Born on 20 April 1871 in Liptovský Mikuláš, Penkala came from a family with mixed Polish-Slovak roots. His father Franciszek Penkala was of Polish origin, born in Andrychów, and was a mining engineer, which probably influenced young Eduard's interest in technology. His mother Maria née Hannel, the daughter of a military doctor, had Dutch roots. After graduating in Bielsko in 1892, in accordance with his parents' wishes, he began studying medicine at the University of Vienna, then continued his education in Dresden, where he studied chemistry and obtained an engineering degree.

After completing his studies, Penkala settled in Zagreb, which became the centre of his professional and inventive activities. His fascination with new technologies and his constant pursuit of innovation soon resulted in a number of patents and inventions that brought him international fame.

One of Penkala's most notable inventions was the automatic pencil mechanism, patented in 1906. This invention revolutionised the way we write and was the forerunner of modern automatic pencils. Penkala then focused on perfecting the fountain pen, which also brought him much acclaim. His innovative approach to fountain pen design made it possible to produce writing tools that were reliable and more comfortable to use.

Penkala was also a pioneer in the field of aviation. His passion and technical interests led him to experiment with aeronautical designs, which resulted in the development of one of the first aircraft in the Balkans. His contribution to aviation, although less well-known than his achievements in writing, was an important step in the modernisation of air transport.

Eduard Slavoljub Penkala died on 5 February 1922, leaving behind a rich legacy of innovation and invention. His work had a lasting impact on the development of writing tools and aviation technology. The company he founded still operates in Zagreb under the name TOZ-Penkala, continuing to produce high-quality office and school supplies. Penkala is recognised as one of the most important inventors in Croatian history and is internationally recognised for his contributions to technological development. His innovations and inventive spirit continue to inspire generations of engineers and inventors around the world.