The NPG (Neue Photographische Gesellschaft) with the director Arthur Schwarz was the first, biggest and for many many years leading bromide photo printing company. After the turn of the century other companies were formed (Rotophot, Aristophot and others) and within a few years and although growing demand, overcapacity and sinking prices/profits led to problems. By about 1906 (exact date not known yet) leading manufacturers formed the “Verein Photographischer Reproduktions-Anstalten GmbH” (P.R.A.) with headquarters at Berlin. Director was the boss of NPG and by April 1907 it represented 13 German and 4 Austrian companies. The aim was to have guaranteed minimum prices and fixed terms and conditions to avoid ruinous competition. I call this a cartel (‘convention’ is probably more correct) although today it has the smell of illegality. Back then it was something normal however, there were some 385 different cartels around by 1905 in Germany.
The logo imprint proves that the card was produced by a member of the P.R.A. and/or a company accepting the NBC price convention terms. It does not identify the individual manufacturer.
The trouble among member companies (Schwarz left director position, new heads were Paul Hamburg (E.A. Schwerdtfeger and Hans Kraemer (Rotophot). In April 1908 NPG and Berlin-Neuroder Kunstanstalten dropped out the P.R.A. and the convention was put aside. Finally by August 1909 the price cartel ‘Neue Bromsilber Convention’ (NBC) was set up. Still around by the early 1930’s as entries in photo trade address books show. The president at that time well known Heinrich Ross from Rotograph Bromsilberdruck GmbH, Berlin.
A more detailed article on the bromide photo manufacturers, cartels and conventions (also for other type of cards) and the general situation of the German ppc printing trade 1907-10 is found in TPA issue 23.