After reading forums and experts reviews, I have concluded that most users and professionals do not like cartridges of this model. Many of them are not able to be used for more than 2 refills. I believe that the problem lies not in the cartridge. Most of the people, who try to fulfill these cartridges do not have enough perseverance and desire to bring the work to the end. And of course, prevent all sorts of bad advice on forums, such as: "I fill these with HP toner 1005", "terrible cartridges! I have not disassemble them, and simply fill it with toner through the cork." And what can we learn from these fellows? In this tutorial I'll will explain you, how to refill these cartridges. I will reveal a few secrets that will help you during refilling Samsung MLT D101S MLT D111S. Follow the instructions and you can easily refill these cartridges up to 15 times, it's guaranteed!