The risk of International Klein Blue

A visitor of an art exhibition in Belgium was so impressed by the exhibition that he had a work of art. The visitor walked through the work Dry blue pigment, from the French artist Yves Klein. 
@ BOZAR

International Klein Blue (IKB) was developed by Yves Klein in collaboration with Edouard Adam, a Parisian art paint supplier whose shop is still in business on the Boulevard Edgar-Quinet in Montparnasse. The uniqueness of IKB does not derive from the ultramarine pigment, but rather from the matte, synthetic resin binder in which the color is suspended, and which allows the pigment to maintain as much of its original qualities and intensity of color as possible. The synthetic resin used in the binder is a polyvinyl acetate developed and marketed at the time under the name Rhodopas M or M60A by the French pharmaceutical company Rhône-Poulenc. Adam still sells the binder under the name "Médium Adam 25".
In May 1960, Klein deposited a Soleau envelope, registering the paint formula under the name International Klein Blue (IKB) at the Institut national de la propriété industrielle (INPI), but he never patented IKB. Only valid under French law, a soleau enveloppe registers the date of invention, according to the depositor, prior to any legal patent application. The copy held by the INPI was destroyed in 1965. Klein's own copy, which the INPI returned to him duly stamped, is still extant. In March 1960, Klein patented a method by which he was able to distance himself from the physical creation of his paintings by remotely directing models covered in the color. LINK BOZAR LINK NOS (in Dutch)