He was the owner of the printers in Cieszyn, which had been in the family since 1806. During his time as owner the family printing works became one of the biggest and well known in the Austrian Monarchy, and Prochaska received the titles of; bookseller to the Royal Imperial Court, printer to the Royal Imperial Court, and honorary imperial councillor. He was also awarded with the Franz Joseph I medal. He published in all European languages and many others. Karl Prochaska died in 1920.
       He was awarded with the title of honorary citizen by the Town Council on 30 April 1904. The grounds for the honour were given as above all his achievements as the owner of a firm which began small and grew into a large company, trading beyond the borders of Silesia. It was remarked that to a great extent Cieszyn became a cultural and artistic centre as a result of Prochaska’s enterprise. Also stressed was the importance of the influential newspaper Silesia which Prochaska published. It began as a weekly, later becoming a daily newspaper with Liberal leanings, and was regarded as the unofficial media organ of Austrian Silesia.a