The Art of Manliness has an article on Wax Seals: A History and How-To
The use of wax seals largely disappeared along with the popularity of handwritten correspondence. But judging by the surprising number of sealed envelopes I receive from AoM readers, the practice has certainly not died out completely among those who still practice the art of letter writing. The appeal? They add an element of distinction to your correspondence, and, perhaps just as importantly, give you a chance to play with fire! If you’ve ever been curious about wax seals, today we’ll cover everything on the subject from their history to how to make them yourself.
While I have never used wax seals, as a consequence of having visited China several times as part of our adoption process, each member of our family also has their own personal chop:
Chinese seals are typically made of stone, sometimes of metals, wood, bamboo, plastic, or ivory, and are typically used with red ink or cinnabar paste (Chinese: 朱砂; pinyin: zhūshā).
I have not had very many occasions to use my chop, though not for lack of trying. Now that I think of it, I will have to see about using it to sign my next employee evaluation. Just because.