Trying to make something xRay proof is another issue all in itself. I recently had an issue with an order and when I spoke to the vendor they said they used carbon paper to conceal the contents, as soon as they told me that I felt like saying well you might as well have just written illegal drugs inside please inspect me Mr custom person. All packages are scanned entering AU, trying to conceal the contents like that guarantees an inspection because is looks totally suss on the scanner.