Focused on Gold, but equally applicable to anything else of high value. Obviously it is focused on US shipping. Extracted from an article just written by President of Miles Franklin, one of the larger bullion dealers in the US. Emphasis below is mine. Note especially the last sentence.
Packaging is the most important step in the process. It is very important to make sure gold coins are securely wrapped or packaged tightly in tubes. Even with tubes, it is not a bad idea to stuff a cotton ball inside the tube to eliminate rattle. The bottom line is one should err on the side of safety rather than under-protection.
The only way to securely mail gold is through the US post office. The post office offers a program called Priority Flat Rate. With free shipping supplies, Flat Rate options, and no weighing or calculating, the Priority Mail Flat Rate service is a simple way to ship. Delivery times are typically two days [except with registered mail, which this article covers - registered mail may take substantially longer to deliver due to the security requirements -68], and Priority Mail Flat Rate Boxes are both fast and affordable.
After you seal the Flat Rate box with strapping tape, you will need to cover all the edges of the box top, bottom, and center with postal registered tape. Unfortunately, it is hard to find postal registered tape any place other than behind the counter at the post office; however - like the Flat Rate box - it too is free.
First, cut the registered tape to size, and activate the adhesive on the back with a damp sponge or paper towel. After sealing the box with strapping tape, apply the registered tape over all boxes seams. Anywhere someone could stick an exact-o knife blade into the box must be covered with the registered tape.
The last step involves simply addressing the box, and obtaining the registered receipt. You will declare the value of the contents on the registered receipt, but need not tell the postal employee what you are sending. My personal favorite response is "machine parts," but as long as the package does not contain hazardous material, it is none of their business!
In 23 years of business, we have never lost or not received a sent registered and insured package.
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