Most stamp dealers have a specialization, some field of (philatelic) interest which make them stand apart from other dealers. But there are few stamp dealers like Willem van der Bijl, whose small shop in the historic city center of Utrecht in the Netherlands belies the importance of his collection of North Korean materials, both philatelic materials and propaganda posters/paintings.
A book about the posters collected by Willem van der Bijl and another collector, Ronald de Groen, was published in Dutch in 2015. This was essentially a museum catalogue for an exhibition in a Dutch museum (Drents Museum, Assen). This book, beautifully produced by WBOOKS with many large full colour images, is unfortunately now out of print, but at least those materials have been available for public view before. This is unfortunately not true for the North Korean philatelic materials in his collection. That is why we are publishing another set of his materials on the KSS website and in KP magazine.