There's an interesting copyright statement in this DIY Rietveld furniture guide that Artikel 16b of the Netherland's Auteurswet allows individuals to make personal copies of the designs for their own use, but not sell or transfer the physical chairs to others.
@th I've seen copies of the topright corner chair a few times in second hand shop. I think one is for sale in a shop in Amsterdam north at the moment. clear copyright violation. :)
@wmd according to the book they have "[Cassina en Rietveld originals] hebben van ons exlusief het recht gekregen om bepaalde meubels van onze grootvader op de markt te brengen", so it might be a licensed copy.
@th Amusingly, or perhaps interestingly, I made the Rietveld Red and Blue chair from the original plans under that provision back when I was in high school in the Netherlands. Fun project.
@bruienne according to this book, Rietveld also published “meubels om zelf te maken” guides as well as selling kits for some of the designs.
@th I am _pretty_ sure we used those guides in our wood shop class - they looked very old and quite different from contemporary woodworking instructions. That said us high schoolers had no real trouble following them and ended up with fairly accurate reproductions of his designs.