The liquid phase epitaxy growth of single-crystal iron garnet thin films of composition Gd3−x−yLuxBiyFe5−zGazO12 is discussed. The Bi, Lu, and Gd contents are identified for which the garnet films have in-plane magnetization as well as sufficiently large Faraday rotation and can be grown at relatively small melt undercooling temperatures. The results of extensive characterization of the magnetic and optical properties of these garnet films as a function of melt compositions and undercooling are reported.