"Bubbles" in processed Portra VC160

I had some film developed yesterday at a lab in Chicago. My 4 x 5

sheets seems to be okay, but the 120 Portra VC 160 roll has what

appear to be isolated bubbles in some of the exposures. They are in

the emulsion side of the film and are just barely visible without

magnification with a loupe. On magnifications, they seem to have well

defined boundaries and look like the bottom most layer of the emulsion

has separated slightly from the others, but the image seems to be

okay and not distorted. Otherwise, the film seems well developed.

 

The film had been sitting in a roll film holder over a period of about

a month and taken in and out of the cold, but it was never much below

freezing when I did it. I've had lots of 120 film exposed in the same

roll film holder and developed by different labs, and I regularly

develop b/w 120 and 4 x 5 film myself, and I don't remember seeing

this before.

 

Could this be a fault in the film itself, related to environmental

conditions, or possible some result of faulty processing? The problem

is more annoying than anything else since I scan my negatives and I

can correct quite a lot by cloning.

Sounds exactly like stabilizer scuzz to me, if they don't change out their super rinse and stabilizer tanks regulary, this will happen. You might try taking it to another lab and ask them to re-rinse and stabilize the film.