I had a IPP capable printer that wasn’t showing up for AirPrint, and was able to solve that with a (relatively) simple static mDNS entry in my DNSMasq config, which I already had running on our router.
The article says the formats need to include ‘image/urf’, which afaik wasn’t true in 2017, and there may be other salient differences these days. We subsequently moved to a newer printer w/built-in AirPrint.
I see that note, and the wording on it confuses me. My recollection, and some confirmation from this article [1], is that I was using handyPrint when connected to the mac via USB. At the time of the blog post I wrote, I was switching from usb to ethernet, and discovering that I didn’t need a separate computer to make the bonjour / mDNS announcements.
It’s still reliant on the printer handling the correct print protocols (so that CUPS isn’t needed to translate), but my specific printer did work.