It took over 2 years to realize and implement a new style for PTT NEDERLAND. This took place at the end of the Eighties and after many years of preparations, this completely new style for the dutch company was effective by the end of 1989. I counted almost 180 people who were involved in executing this operation. The result was another new and completely modern, almost timeless house style, after many years of illustrious and classic house styles ( Piet Zwart ao) . Another classic and impressive house style was realized. Studio Dumbar was responsible for this new dutch design classic and it was the last house style before PTT was split up into a number of private companies of which KPN and TPG were the main ones.
With this split up the design department for which PTT was famous, ceased to exist. This department was solely responsible for many of the designs for which PTT became famous. Piet Zwart would not have had the chances as a graphic designer were it not for the orders PTT has given him. The portrait at the head of this article is the self-portrait of Piet Zwart. The greatest of all PTT designers.
http://www.ftn-books.com has the beautiful publication on this change of house style of PTT , published by PTT publishing, with the text of Paul Hefting available.