Blood

125 years of the discovery of blood groups (1900)

Written in: Dutch • Randy Koo • October 12, 2025

Karl Landsteiner became famous for developing the modern blood group system by identifying the presence of agglutinins in the blood. He did this by investigating the way blood reacted when mixed. Sometimes...

World Blood Donor Day June 14, 2021

Written in: Dutch • Randy Koo • June 29, 2021

In 2004, the World Health Organization (WHO) designated June 14 as World Blood Donor Day. A special day on which attention is drawn worldwide to the importance of voluntary and unpaid blood donation. On this day, special attention is given to those who donate their blood...

Vincent Tromer over North Sea shells: So don't buy it.

Written in: Dutch

Peter over Delta Works: The Netherlands and water with climate adaptation: Thank you very much for the nice explanation of the design.

Written in: Dutch

Lars over Delft Blue Ceramic stamp a 'deception stamp': Now just get those blueprints out of the catalog..

Written in: Dutch

Erik Boeré over Delft Blue Ceramic stamp a 'deception stamp': The best solution is probably to ignore the ceramics stamp altogether. Fortunately, as the NVPH/Catalog Committee, we already have…

Written in: Dutch

Yvonne Kruse over The piss-pots of Tilburg: What a nice article, Willem!

Written in: Dutch

Willem over Stamp Day 2026: “I would like to know . . .?”: The Delta stamps can already be found on Marktplaats. A beautiful design! In my opinion, that is an example of how collectors want it.

Written in: Dutch