Someone asked me about laser printer consumables, specifically toner vs drum unit. That’s a fair question. The drum unit is the gotcha consumable that people sometimes forget about.
Why sometimes? Because on higher-end laser printers, the drum and toner are a single unit. On monochrome HP Laserjet office printers, for example, when you replace the toner, you get a new drum. Or a different drum, at least.
From a technical standpoint, the drum is the part that holds the image before it goes onto the paper. The toner is the ink that the printer melts onto the paper. If you’re low on toner or have a worn-out drum, print quality suffers. Faint print usually means you’re low on toner. Dark bands across the page, or ghost images of previously printed pages mean you have a worn-out drum.
On cheaper printers, the drum and toner may be separate units. Drums usually last for more pages than toner cartridges. So keeping the drum separate lowers the cost of the toner, making the up-front costs look lower. The downside is that eventually you do have to replace the drum, and by the time you do, the store that sold you the printer may not carry the part anymore.
What about refilled toner cartridges? A reputable remanufacturer tests the drum and replaces it if need be. Usually it’s OK to reuse the drum two or three times. But not everyone replaces drums when they should. So I recommend buying cartridges from 4inkjets rather than from random sellers on Ebay or Amazon. I’ve never had a bad cartridge from 4inkjets, but every cartridge I bought off Ebay or Amazon developed problems long before its life expectancy was up. That’s the difference between remanufacturing toner cartridges and merely refilling them.
One more difference: Toner can sit around essentially forever. It will have an expiration date on it but you can safely ignore it. Once you open the drum, it does slowly deteriorate over time due to light exposure. Drums have a long life, but it’s not infinite.
Laser printers always cost less than inkjets once you factor in consumables. But when you’re shopping for a laser, make sure you find out whether the drum is separate or integrated. If it’s separate, find out what it costs, how long it lasts, and where to get one.