PRA, Verein Photographischer Reproduktions-Anstalten GmbH

According to the TPA site where there are more details, PRA was founded around 1906 and by 1907 comprised 13 German and 4 Austrian companies. The firms on the current site which published cards showing the PRA logo are BNK, DECOBE (?), EAS, GGCO, K&CM, KJUNO, LL, NPG, OPG, PFB, PMB, RPH, RPH ROSS and RPH SBW.