I do have one of the photoengravings from DSP&P--the halftone of the Jefferson depot. These were around for a long time after the book was printed and were sold off as souveniers--mine came from the Railroad Memories shop in Silverton about 20 years ago and they had a box of the plates from that book. I can still print from that plate with no problem though I think it was made about 1949. The letterpress printer the Rocky club used in Denver, and I think it was World Press, had a limited supply of Linotype metal (an alloy of lead, tin, and antimony) and the type was set using this metal. After they had set as much type as they had metal, they would print as much of the book as they could, then melt the type down and set the next text and picture captions, and so on. At completion of the book, the only printing materials left were all the plates (photoengravings) and the last chapter or two of type. Any reprinting would have required a complete resetting of the type. This same printer printed the supplement book some years later, but they are long gone.
In the letterpress era, books were stored after printing in steel trays called galleys, and each page took up one galley. Unless there was a prospect for reprinting, the book was usually "dumped" after a set period of time, but the separate plates for the illustrations were saved. It was not uncommon for large printers to have tens of thousands of galleys in storage. The old Kistlers in Denver filled the basement under their downtown shop with galleys. Offset replaced all this, and now digital methods are competing for the short run work. Letterpress plates, and even the type, lasts indefinitely. Offset film, properly stored, has an indefinite life. Offset plates have a limited life, and electronic media is anyone's guess. With the rush to create and store everything in an electronic format, I forcast that there will be a huge black hole of lost information and media 100 years from now for our current time period. Stick with steam, stick with letterpress for printing (and I may be about the only printer in Colorado still capable of printing a book from metal type in the traditional manner). I am not soliciting work, however.
fritz
