It seems the general consensus is that the film shields just encourage X-ray techs to increase the intensity.
Would such a bag at least get by museum and possibly train inspections?
They're a big scam.
I don't know why people are buying into that.
It's simple: the inspector either sees inside the bag (so your film gets the radiation), or he doesn't.
So what do you think will happen, if the inspector sees a big black blob on his screen, and no way to see inside?
He'll let it pass?
Of course not.
He'll open the bag, pour everything into a basket and scan scan it.
(Btw, they can't change the intensity of the machines. That would require a technician, and the controls are inside the machine -you need to open it up to access them- for safety reasons.
The inspector can change just the amplification of the signal.).
That said, I've never had an issue with carry-on scanners.
I've also never, ever seen anyone posting a single shot ruined by carry-on scanners, regardless of film or number of passes.
I've travelled with Delta 3200, pushed Tri-X (1600), pushed Provia 400X (1600), HP5+, etc., you name it.
4 passes minimum.
Never an issue.
No densitometry tests, but I couldn't discern the slightest difference, in prints an scans.