Kaj Franck (1911-1989) trained as a furniture designer and interior designer in Helsinki and after graduating in 1932 he worked as an illustrator, textile designer and interior decorator. In 1945 he joined the ceramic company Arabia and became their chief designer but also worked in the late 1940s for Iittala and in 1951 he was appointed artistic director of the Nuttajärvi glass works so he is now more widely known for his glass and tableware designs.

In 1955 he was awarded the Lunning Prize and travelled first to the United States and then to Japan.

The Kartio tumbler was designed in 1958 as one of several simple and practical pieces of table glass that were produced for both domestic use but also for commercial restaurant and cafe use and also for export. Kartio means cone and the shape could not be simpler … a truncated cone with a flat base and angled sides. It stacks easily and the smooth, slightly-rounded thickening of the base not only gives the tumbler a good balance when picked up but helps to prevent the stacked glasses being chipped and scratched.

One definition of good design is that there is a point reached in the design process where nothing can be added and nothing taken away without spoiling the form of the work and that is certainly true of the Kartio tumbler. The simple shape has beautiful clean lines and proportions and it is obvious that if, for instance, the angle of the side was made steeper and the top tighter then it would not be as easy to drink from or as easy to stack and if the top was taken outwards it might look more dramatic but would probably be less stable. The design has been refined to a point where visually and physically it has a strong sense of equilibrium.

Another yardstick by which to judge good design is that it should express the best qualities of the material and its form and any decoration should reflect and make the best of the characteristics of the manufacturing process and, unless there are very good reasons, that form should take as the starting point its ultimate function. The Kartio tumbler certainly ticks all those boxes. Perhaps some people would argue that this makes the glass rather stark or even slightly boring and some might use words like functional or utilitarian pejoratively as an implied criticism but it is the simplicity of the design that makes it timeless. Some good design is good because it simply and quietly gets on with the job it was meant to do. The Kartio glass is coming up to its 60th birthday but my guess would be that anyone who is not a design historian would be hard pressed to guess its age.

Over the years Kartio has been made in coloured and clear glass and is still in production by Iittala who now control the Nuttajärvi works. The catalogue from the design museum in Helsinki, Kaj Franck Universal Forms published in 2011 has a short but interesting section on which colours were chosen and why and why and when over the years new colours were added and some colours stopped. Even the simplest design can be influenced by or set new fashions.