My mostly-nice color inkjet has two tanks of black ink; a big one for B&W documents, a small one for color documents. By default my Mac sends all its jobs in color and the printer isn’t smart enough to realize that the whole document is monochrome so really, the cheaper big tank will work just fine. I want to default printing to grayscale.
Irritatingly, you can’t do this with the obvious way in a Mac. You can create new printer option sets and save them as new profiles, but there’s no way to change the default profile.
But there is a way, via the CUPS web interface hiding underneath MacOS. It never occurred to me that this would be there! The instructions in the linked blog post worked just great for me, I even have the same kind of printer. Two wrinkles.. I had to choose the second of the two printers, the first had no print options associated with it. And the “Greyscale Printing” option appears twice, I had to set both to make it work.
This may save me literally dollars a year.