I searched in this forum to check if this had been posted somewhere else but I didn't find anything.
I just found this last night, there is a German company making white printer toner cartridges for numerous HP, Canon and Lexmark laser printers.
https://www.ghost-white-toner.com/
You just swap out the black cartridge for the white, I've seen printed examples on a railroading site, and there are several YouTube videos about it.
The cartridges are a bit expensive but one should last you several years.