The IF boat was designed in 1966 by Tord Sundén, who had already been involved in designing the Nordic Folkboat in 1942. It was originally called "International Folkboat", but was not allowed to keep this name because it was not registered as an international class, but only as a Swedish and later also Danish national class.
The IF boat is based on the design of the Nordic Folkboat. Compared to this, it was given a higher freeboard, and the transom and stem were slightly modified. The superstructure was extended in front of the mast to provide more space below deck. Because a GRP hull is lighter than the wooden hull of the Nordic Folkboat, the keel weight and thus the sail area could be increased. The sail carrying capacity is 3.95. To improve sea safety, the boat was equipped with a self-draining cockpit.