Abstract: Set forth herein are processes and materials for sintering dense thin green films comprising lithium-stuffed garnet powder and a binder to obtain sintered lithium-stuffed garnet thin films. Some of the processes, herein, include providing a first setter and a second setter, wherein the first setter and second setter each include at least 5 atomic % lithium (Li) per setter; placing the green film on the first setter; placing the second setter within 2 cm of the green film but not in contact with the green film; and heating the green film to at least 900 C.