Coats of Arms. Tony, I think the Dutch stamps are really quite nice. I surely won't discriminate against them.
For a comparison, please see coats of arms from Switzerland, mid 20s.

I think perhaps the Swiss stamps have clearer contrasts between light and dark whereas the Dutch ones seem to predominate a couple of closely related colors and as such the design does pop as much. The Swiss design is perhaps simpler.
All though a matter of taste.
-Larry