An ice maker assembly (52, 210) for an appliance comprising: a housing (54, 212) defining an interior volume; an ice tray (70, 218) horizontally suspended within the interior volume of the housing (54, 212) and including: a metallic plate (76, 220) that has a bottom surface (80, 224), a top surface (78, 222), and an edge portion (132, 316); a containment wall (82, 226) that extends upward from the top surface (78, 222) and along the edge portion (132, 316); and a grid (100, 232) that has at least one dividing wall (94, 230) that extends across the top surface (78, 222) between the containment wall (82, 226) on opposing sides of the ice forming plate (76, 220); and a fluid line extending into the interior volume of the housing (54, 212); wherein the containment wall (82, 226) and the grid (100, 232) have a material with a lower thermal conductivity than the ice forming plate (76, 220), and wherein at least one substantially clear ice piece (98, 236) is formed in the ice tray (70, 218); characterized in that, the top surface (78, 222) of the metallic plate is substantially planar; the ice tray (70, 218) is rotatably coupled with the housing (54, 212); the fluid line has an outlet positioned above the ice tray (70, 218) and is configured to dispense water over the top surface (78, 222) of the ice forming plate (76, 220) to be retained by the containment wall (82, 226) and the grid (100, 232); and the ice maker assembly (52, 210) further comprises a cooling source (102, 238) thermally coupled to the bottom surface (80, 224) of the ice forming plate (76, 220) and configured to freeze water retained on the top surface (78, 222) in a bottom-up manner; and wherein, the lower thermal conductivity of the grid (100, 232) compared to the ice forming plate (76, 220) aids in forming the substantially clear ice piece (98, 236) in a bottom-up manner. a housing (54, 212) defining an interior volume; an ice tray (70, 218) horizontally suspended within the interior volume of the housing (54, 212) and including: a metallic plate (76, 220) that has a bottom surface (80, 224), a top surface (78, 222), and an edge portion (132, 316); a containment wall (82, 226) that extends upward from the top surface (78, 222) and along the edge portion (132, 316); and a grid (100, 232) that has at least one dividing wall (94, 230) that extends across the top surface (78, 222) between the containment wall (82, 226) on opposing sides of the ice forming plate (76, 220); and a metallic plate (76, 220) that has a bottom surface (80, 224), a top surface (78, 222), and an edge portion (132, 316); a containment wall (82, 226) that extends upward from the top surface (78, 222) and along the edge portion (132, 316); and a grid (100, 232) that has at least one dividing wall (94, 230) that extends across the top surface (78, 222) between the containment wall (82, 226) on opposing sides of the ice forming plate (76, 220); and a fluid line extending into the interior volume of the housing (54, 212); wherein the containment wall (82, 226) and the grid (100, 232) have a material with a lower thermal conductivity than the ice forming plate (76, 220), and wherein at least one substantially clear ice piece (98, 236) is formed in the ice tray (70, 218); characterized in that, the top surface (78, 222) of the metallic plate is substantially planar; the ice tray (70, 218) is rotatably coupled with the housing (54, 212); the fluid line has an outlet positioned above the ice tray (70, 218) and is configured to dispense water over the top surface (78, 222) of the ice forming plate (76, 220) to be retained by the containment wall (82, 226) and the grid (100, 232); and the ice maker assembly (52, 210) further comprises a cooling source (102, 238) thermally coupled to the bottom surface (80, 224) of the ice forming plate (76, 220) and configured to freeze water retained on the top surface (78, 222) in a bottom-up manner; and wherein, the lower thermal conductivity of the grid (100, 232) compared to the ice forming plate (76, 220) aids in forming the substantially clear ice piece (98, 236) in a bottom-up manner.