Switzerland has 26 cantons (states), which have been charged by the Swiss federation for various political tasks on their own. One of these tasks is the organization, mediation and collection of culture on canton level. The current stamp is coming from the Canton Library Ticino, one of the Italian speaking cantons in the South of Switzerland. The library collects, among other tasks, the published books on canton level or written by inhabitants from Ticino. In the middle, circumscribed by the library’s name, the emblem of Ticino can be seen, composed of two halfs, one red (left) and one blue (on the right side). The current stamp is the old version and can mostly be found on old books, kept in the depot.
As comparison, here the new version of the stamp. The only real difference is the change from an oval to a round form.