Postcards as a reflection of German-Czech contradictions in the period of the Badeni crisis in the late 19th and early 20th centuries have more than once been the subject of study. The research novelty of this article lies in the fact that the problem is examined not through postcard images themselves, but from the point of view of the primary functionality of postcards as a means of communication and a commercial product. The author focuses on commercial, postal-technical, consumer practices, institutional and legal aspects, as well as the reception of postcard messages, both individual and public. Various national associations and private entrepreneurs, main producers of postcards, oft en deliberately radicalized their content in their political or commercial interests. The specificity of the postcard as a means of postal communication and its mass appeal served as the basis for unique practices in mobilizing supporters and criticizing opponents by “cartographical attacks”. Even the design of postcard forms was a means of national struggle and expression of personal position. Publishers of the respective orientations designed them in the “German” or “Czech” spirit, while the official position was to refuse any name for this postal product. At the same time, the numerous variants of handwritten edits concerning all the constituent parts of the postcard (technical design of the form, address, and stamp) allowed users to state their position on the national question. Th e legal side of postcards’ production, functioning and existence was determined, on the one hand, by conditions which were common to other types of printed matter, in particular, by the liberal press law of 1868, and, on the other hand, by postal regulations that periodically withdrew certain postcards from circulation. All this became the subject of litigations and debates in parliament and thus provided a way for postcards to enter the public sphere and, accordingly, served to attract further public attention to the national conflict and its aggravation.