Photo-Lab-Index, The Cumulative Formulary of Standard Recommended Photographic Procedures - I have two the first is copyrighted 1949 my second is 1970 I do not know when it was first published or when they dropped its publishing. The binding was loose leaf in an expandable binder, and came with a membership that was renewable. Periodically you would receive a pack of updated information, and a replacement instructions for what to remove and what to add. The binder contained information about all the brands of Film, Printing mediums, and Chemistry plus formulas for making your own photo chemicals and covered all brands. It also covered film speeds, and push/pull development, and charts and detailed data on all these products. It covered lighting techniques, flash bulb guide numbers, darkroom designs, mounting procedures for exhibition prints. Lighting placement for portraits, and photo copy.... basically everything you wanted to know was in the volume. It was a prize possession to own.