In 1957, the Royal Leerdam Glass Works commissioned Haanstra to make an informative promotional film in black and white. This resulted in the accomplished 25 minute Speaking of Glass. On entering the factory, however, Haanstra noticed that a mechanical stacking machine was malfunctioned because of one broken bottle. Amused by its robot like but futile movements, Haanstra agreed to make the film, but only on condition that he could make a separate short on glass. The film gives an intriguing view of the process of glass blowing and the mechanical way in wich glass objects are made. Glass, his greatest success to date, even won an Oscar, the grand prix of Hollywood and Holland's first Academy Award.