This certainly is not Trinity related but as this list is full of experienced people...
For some time (I *think* since I moved to Debian 9 but not sure) I get smeared outputs of my trusty Laserjets. I have both a 4200 and a 4250 (I prefer to buy second hand, Postscrypt, professional printers to first hand consumer-grade stuff). Not always, tends to happen more when printing double sided and less when the printer has been off a while.
I had thought this was old cartridges and I had to survive until I change them, but today I had to print some older stuff that dwells on my old hackintosh and... beautiful print! No problem at all.
So. Then it's Linux, not the printers.
I'll soon make a test install of the latest openSuSE and see if there is a difference. Both MacOS and Linux using Cups, I'd have thought that standard, Postrcrypt drivers would be the same.
Thierry