Today I spoke to Rick at King's Wax. I called to order some sealing wax. I explained that I hadn't come across him online before this week and I wanted to try his wax - both original (breakable) and mailable (flexible) varieties. He claims to be the largest sealing wax manufacturer in the world, and I have no reason to doubt him. I believe there are only 3 manufacturers of "real" sealing wax, as opposed to the ones that are mostly paraffin. If the quality of his wax as I expect, his prices are reasonable for what he is offering. Heretofore, I have favored J. Herbin but I am open to trying another brand. (Hey, I'm mature. I even changed the brand guitar strings I have been using for 40 years, last year.)
I like to have some breakable wax in my stash, for certain events, but I use far more flexible wax because I put it through the tortures of the mail system. Before the flexible formulations were available, my sealed correspondence frequently arrived chipped or completely broken. The flexible wax goes through the mail well, but one compromises the recipient's thrill of cracking the seal when opening the correspondence. In fact, I ceased using the company from whom I originally purchased wax - in my youth, they were the only source of which I was aware in the US. I ceased purchasing from them because they only sold the fragile wax.
Recently, I viewed their long over due, newly updated web site. It surprised me to see they were now offering flexible, mailable wax. I have a feeling that what they offer is King's. I didn't ask Rick, when we spoke.
I'll post a review of the new wax when I receive it -- probably the end of next week or the very beginning of the following. It will be shipped today (1/7) and is coming from Canada.