Laser toner cartridges can be expensive, the cost and fast shipping is the reason I bought this brand. I usually try different brands of non-OEM cartridges and the first black cartridge of this brand I used was permanent, the other one in the box seemed to have leaked into a bag. When I use color cartridges, I immediately see the difference in quality compared to OEM cartridges. I calibrated my machine and tried again with the same result.