ILs have proved to be efficient solvents for the dissolution of high amounts of cellulose in rather short time. As has been summarized in Sect. 5.2, numerous chemical derivatization reactions have been realized successfully in these novel homogeneous reaction media. However, with increasing gain of knowledge it became apparent that ILs also possess some specific disadvantages that can hamper their use as cellulose solvents in technical scales. Some of these issues are techno­logical aspects that are currently studied and can be expected to be solved in the near future; e. g., IL cost, purity, and recycling availability. Others are intrinsic restrictions related to the physical and chemical properties of ILs, i. e., limitation that cannot be avoided but only be attenuated.