Strangle Squiggly Lines on BW 120 Negatives

I have just started processing and developing my own 120 film, and my first few rolls turned out well, but with the last few, I have noticed these odd, dark, squiggly lines that go through the entire length of the negative. The lines are uniform throughout each roll, but not from roll to roll (in some of them, there are two lines on either side, and some have it straight in the middle). I was thinking it could possibly be a light leak, but not sure if that explains how they are so squiggly.

I am using a Mamiyaflex C2 with Tri-X 400TX Kodak film . I have also used the camera before and have never experienced this problem.

Any ideas about what this is and how I can fix it or prevent it in the future?

Photographs of the negatives in archival sheets are attached.
https://drive.google.com/open?id=1gAky-2alu_PW-qDOLI8TJgn2g6IlTQ9U

Welcome to Photrio.
That might be a consequence of uneven fixing. Try re-fixing the film in fresh fixer.

They look like flow marks of some sort. Tell us about your development -- developer, temperature, agitation, etc. Also are they (were they) completely dry when you took the picture -- as in several hours?

Looks like fogging, a good first step might be to check the bellows for light leaks.

If fogging, was the film x-ray on an air flight?

Yes, that does look a bit like some example pics i've seen of xray damage: https://www.kodak.com/global/en/service/tib/tib5201.shtml#SEC47

Sirius Glass said:

If fogging, was the film x-ray on an air flight?

Click to expand...

DavidJRobertson said:

Yes, that does look a bit like some example pics i've seen of xray damage: https://www.kodak.com/global/en/service/tib/tib5201.shtml#SEC47

Click to expand...

Thanks guys, I think this is exactly what happened. I did fly recently with the film so that would explain it. Looks just like the examples. I've never experienced this before so thanks for the help!

presume this film was checked with your baggage and not carried on ?

Sirius Glass said:

If fogging, was the film x-ray on an air flight?

Click to expand...

DavidJRobertson said:

Yes, that does look a bit like some example pics i've seen of xray damage: https://www.kodak.com/global/en/service/tib/tib5201.shtml#SEC47

Click to expand...

robbisc said:

Thanks guys, I think this is exactly what happened. I did fly recently with the film so that would explain it. Looks just like the examples. I've never experienced this before so thanks for the help!

Click to expand...

canuhead said:

presume this film was checked with your baggage and not carried on ?

Click to expand...

Never check film in luggage. Only carry on the airplane.

Sirius Glass said:

Never check film in luggage. Only carry on the airplane.

Click to expand...

Yeah, apparently the scanners used for hold luggage are somewhat more powerful than those used for hand luggage. I recently took film (including one roll shot at EI 3200) through 2 airport hand luggage xray machines with no issues.