Thanks for the link.
“Small-volume braille printers cost between $1,800 and $5,000 and large-volume ones may cost between $10,000 and $80,000.”
Well, I guess that settles that option. Perhaps a print shop would have one, but I suppose it would not be cheap to use if they have to recover their investement. I would have to know that my recipient were blind to take that option.
OTOH, I also thought: I could record my voice (either reading my letter or giving a summary), then post on the web with a password, and put a QR code in the letter to an URL that includes the pw as an argument. But a blind person wouldn’t see the QR code. So that kills that idea. In principle, such a practice could theoretically be standardised with the QR code in an expected position.