When I go through numerous illustrated books from the late 1970s and early 1980s, there is a definite gain in quality with the introduction of the first E-6 Ektachrome films. Before, only Kodachrome films appear to have enabled double-page color reproductions from the 35 mm format. Ektachrome and Agfachrome seem to have been well established in medium format photography, but especially the latter had noticeable grain even at the slow speed of ISO 50/18°. In comparison, the new E-6 films such as Ektachrome 64 (1976), Fujichrome RD100 (P) (1978) or Ektachrome 100 (EP(P), date ?) showed fine grain and high resolution even when judged after today's standards. The new process apparently enabled also a considerable improvement in the stability of the dyes, as Ektachrome and Fujichrome films from that era don't show fading. In comparison, Ferrania/Scotch/3M and the first generation of E-6 Agfachrome slide films remained unsatisfactory in this regard - at least in the latter case, for patent reasons, as Agfa couldn't use the more stable Kodak-type color couplers. Early E-6 Agfachromes have therefore turned muddy brown, Scotchchromes purple. The latter, rather mediocre, were often sold at a discount price and under generic brands. In retrospect, the introduction of E-6 seems to have caused the following consequences: Kodachrome films started to lose customer (including amateur) preference, as there were now suitable alternatives with similar and continously improved quality, higher speed, faster processing (for pros) and a lower price (for amateurs). Other manufacturers were either forced into compatibility (Agfa and Ferrania) or finally withdrew from the market (such as Ansco/GAF or ORWO). Are these conclusions correct? - I have read that the introduction of a high-speed Kodachrome film was canceled due to insufficient demand.