Looking for a way to make a paint which block scanner
What kind of scanner are we talking about? Ix it's an enhanced x-ray scanner, like most first world countries have, trying to block it would be even more likely to raise suspicion than nothing. You can see the technology customs imports airports and agencies that deal with such things have, they can see baggies in a persone stomach at the airport. The scanners can identify what type of material something inside a suitcase is based on it's density. The computer color codes everything based on that, so metal is blue or blsack organic material is orasnhe ect.,. Lead paint could possibly block an x-ray scanner, the vest that they make you wear when you get an x-ray has lead plkates in it, but in a scan, bigspots of obviously very dense metal are not going to go unnoticed.. I think trying to obfiscate the view inside of a package isn't going to work for very long. I think impersonating a legitimate product is a better solution
organic matter inside of wood would have a very faint footprint, being the opposite of a heavy metal in appearance. Aluminum doesn't block microwave any better than mylar, which isn't metal at all, it's just shiny. I company makes baggies rthat they claim can obscure an x-ray image, but like I said, thats a bigger red flag than anything
so basically using rule of camouflage is best practice, compare to covering to make unable to see which create like You said above just its more suspicious which trigger unwanted attention.