There are already two threads about this subject, but in the interest of making it easy to find the information about problem batches, I've brazenly decided to copy a couple of posts from those threads, to make it easy to find the information.
The threads are this one: (there was a url link here which no longer exists) ;
and this one: (there was a url link here which no longer exists)
From Michael R 1974's post #195 in the latter thread:
Some more information about the affected emulsion numbers below in this excerpt from John Sexton's latest newsletter. The full newsletter can be found here
http://www.johnsexton.com/newsletter05-2016.html
IMPORTANT INFORMATION FOR USERS OF 120 FORMAT KODAK PROFESSIONAL FILMS- PLEASE READ
As many readers are likely aware, I have used Kodak Professional film continuously for more than four decades. Over the years I have found Kodak film to be of the highest possible quality and consistency. However, anomalies can occur from time to time. There have been recent reports that appear to be associated with certain batches of 120 format Kodak Professional film.
The problem can easily be seen in the photograph below recently made by William Wetmore. I appreciate William allowing me to share this example with readers. You will notice the word Kodak clearly appears in the sky, along with frame number '13' multiple times. I first became aware of this situation a few months ago when a former workshop participant brought some online discussions on this topic to my attention. Unfortunately, as time has passed, I have encountered a number of students, colleagues, and friends who have experienced this exact problem.
©2016 William Wetmore. All rights reserved.
I have spoken at length with Thomas J. Mooney, Film Capture Business Manager at Kodak Alaris about this phenomenon. He told me "Kodak Alaris has had a limited number of inquiries for similar problems, and that the affected film may have seen some abnormal keeping after it left the factory (e.g. sat in a truck over a hot weekend, etc.). That said, we are taking this issue very seriously and have recently made modifications to the backing paper which we believe should minimize the potential for this type of blemish going forward."
Mr. Mooney has supplied me with the emulsion numbers - which I have listed below – where this latent image print issue could potentially be seen. If you have experienced problems, or have questions or concerns, you should email
Profilm@Kodakalaris.com. This email address goes directly to Mr. Mooney, who will be able to answer your questions, address your concerns, and replace any problematic film you might have on hand or have used.
If you purchase new film you should make sure that the emulsion number, printed on the box as well as the individual foil packages, is higher than the suspect emulsion numbers listed below. All photographers can imagine the disappointment and frustration any of us would feel if this happened to any of our negatives. Please pass this important news on to your photographic friends.
Emulsion numbers that may exhibit the above problem only in Kodak 120 format roll film:
(Emulsion numbers can be found on the film box, the foil wrapper, and printed on the clear edge of processed film near frame number 11.
Kodak T-Max 400
Emulsion 0148 004 through 0152
Kodak T-Max 100
Emulsion 0961 through 0981
Kodak Tri-X
Emulsion 0871 though 0931