First of all, I realize that a majority of people may already know the information that I’m about to present, but I figured I’d present it here anyway for those that don’t know much about it. As a 16mm film collector, I’ve come across various different color stocks, including Eastman, Kodak SP, Eastman LPP, Ektachrome, Fujifilm, Agfa-Gevaert, IB Technicolor, and 3M. I would like to explain, to the best of my ability, the different color characteristics of these stocks for those that are unfamiliar. There are more stocks out there, but these are the ones that I’ve come across during my time as a collector.
Eastman: This is the most common color stock. It was manufactured until the early 1980s. This stock is notorious for fading early, I’ve read in as little as 10 years. The color process is YCM (yellow, cyan, magenta). I believe the cyan layer fades first. What’s left are nothing but shades of pink or red, depending on the print, though some prints can still retain a bit of color. You can identify Eastman stock by looking along the perforation edges, just like with every other film stock.
Kodak SP: SP stands for “Special Process”. This stock was introduced in the mid-1970s and was manufactured until the early 1980s. This stock has better fade characteristics, but it isn’t low fade. I have a few Kodak SP prints that have an orange cast, but still keep a great amount of color. Highly faded prints are nothing but shades of red or orange.
Eastman LPP: Eastman finally (as close as they could) perfected their color stock in 1982. LPP stands for “Lowfade Positive Print”. All of my LPP prints have excellent color. Deep colors, rich contrast, and excellent sharpness. Not much, if any, color correcting needs to be done to LPP prints; however, early LPP prints from around 1982 do have a bit of color fade. It really depends on the print and personal preference. I’ve seen some prints with a slight yellow or orange color bias. The newest LPP print I have is from 1988. Any LPP stock made after 1993 simply reads “Kodak” and makes no mention of LPP.
Ektachrome: Ektachrome has a cool color temperature. The color is great, but it seems to have a bit of a blue hue. Ektachrome can be easily identified by its black perforation edge. The stock markings along the perforations are purple and the stock markings usually make no mention of the stock being Ektachrome.
Fujifilm: The color characteristics for this stock are much better than any Eastman stock preceding LPP. It too, however, is not low fade, at least anything made before 1983 isn’t. When this stock fades, the dyes turn purple. For example, I have three Fuji prints from 1975. One of them has excellent color with no apparent signs of color fading. The second print also has excellent color, but there’s a little bit of a purplish hue. The third prints retains a bit of color, but the whole print is different shades of purple. Around 1983, Fuji made some changes to the stock, now rivaling LPP. I have two Fuji prints from 1983, both with excellent color, no signs of color fade. The year of manufacture is printed along the perforation edge, along with a code for the month of production. If you have a Fuji print that has “83 AJ” printed along the perforation edge, that means the print was produced between April and June of 1983. Additional month codes include JM (January - March), JS (July - September), and OD (October - December).
Agfa-Gevaert: I’m not sure about the fade characteristics of early AG color stock, but some AG stock I have from the 1980s has held up great. There is a bit of color fade on the stocks I have, but it’s not as severe as early Eastman or Kodak SP. AG color stock markings are usually “AG 1S” or “AG 2S”.
IB Technicolor: Need I say more? A gorgeous stock. I’ve seen film prints from the 1940s that still look fantastic.
3M: Some of the 3M color stock I’ve seen also fades to red. It doesn’t hold up that great. 3M color stock seems to be rare, as I haven’t come upon that many prints on this particular stock.
As a side note, when it comes to Eastman/Kodak stocks, there is a date code along the perforation edge. The code consists of a mixture of symbols, those symbols being a square, triangle, circle, a letter X, and plus sign. The date code originally consisted of two symbols, but was expanded to three in 1982. The list of codes can be found here: https://www.filmpreservation.org/userfiles/image/PDFs/fpg_10.pdf