The Croatian National has issued gold and silver collector coins "Slavoljub Penkala’s Innovations" belonging to the series of collector coins "Croatian Innovators" with commemorative motifs featuring Slavoljub Eduard Penkala, one of the greatest Croatian innovators, whose surname Penkala came to be used to refer to ballpoint pens in the Croatian language. His greatest and most famous invention, among many others, is the automatic mechanical pencil, known as "penkala" in Croatian, one of the inventions by Croatian innovators still widely used today, which puts Penkala’s work on the list of cultural and scientific heritage of the Republic of Croatia and the world. The gold collector coin is issued in the 100 euro denomination and the silver collector coin is issued in the 4 euro denomination.
The gold and silver collector coins are minted in brilliant uncirculated condition and will be released for sale on 10 July 2025.
Shown below are the technical specifications and the number of items released.
| DENOMINATION | WEIGHT (g) | DIAMETER (mm) | FINENESS/1000 | QUANTITY max. (pcs) |
| EUR 100 | 31.103 + 0.30 | 32 ±0.20 | 999,9 (gold) | +/100 |
| EUR 4 | 31.103 + 0.50 | 38.61 ±0.20 | 999,9 (silver) | +/1,000 |
The Decision on the issue of gold and silver collector coins "Slavoljub Penkala’s Innovations" was published in the Official Gazette No. 93/2025.
The author of the design of the gold and silver collector coin is Ilaria Longo.
The collector coins were minted and are sold by the Croatian Mint.