[Leica] OT: Laser printer cartridges

[Brian Reid]

I worked on laser printer engineering for a few years in the 1980s. I 
was the lead system engineer for two high-speed laser printers sold by 
DEC, and I have spent a lot of time fussing with laser printers. The 
short answer is that toner is an extremely high-precision substance; the 
size of the toner particles is critical to the functioning of the 
imager, and toner is not generally fungible between brands.

In 2025 I don’t print enough on my laser printer to make it worthwhile 
to mess with toner, and in making decisions like this I rate my time at 
$50/hour. So for myself, it would not be worth it. I’d sell the unused 
cartridge on eBay. But Brother toner will be the same material for all 
of their printers, so you won’t have to fuss with the deep settings if 
you put Brother toner from one cartridge into another.

Toner is very dangerous if you inhale it. We’re talking Black Lung 
Disease level of danger. If you do this, wear a suitably high-quality 
respirator that is rated for the particle size. The printers whose 
design I managed used toner that had 30-micron particles. I took a quick 
look at the Brother printer specs and I’d guess that they use 15-micron 
particle sizes. For myself, I would use supplied air and not a 
respirator to mess with 15-micron toner particles. I always used a 
scuba-style breathing apparatus when I had to get involved with live 
30-micron toner. Our company’s service technicians didn’t. I have no 
data on how many of them are still alive.