We used 3-4 different suppliers of Brother MFC-L3770CDW toner cartridges. We usually write documents that are mostly text, but we highlight a lot of text to make it stand out. With other toner cartridges we've used, the highlighted areas in our documents are fading in various places and the text is blurry in certain places, obviously affecting the quality of our presentation. So we wanted to test them as soon as we got subscription. We immediately removed the toner cartridges in the printer, which still contained a lot of toner, and used Aboit. We did a printer calibration and then printed some documents. We were pleasantly surprised! No fading and text was crisp and clear. As a result, especially considering the current price, we have ordered several more sets.