Methods for continuously casting metal product directly from molten metal confined and solidified in a casting region defined by upper and lower, cooled, endless, flexible, traveling, casting belts supported by belt support systems including back-up rollers in respective upper and lower carriages and laterally defined by first and second traveling side dams. The back-up rollers and belt support systems shape and maintain the casting region for improved heat transfer between cast metal and belts for improved product uniformity and enhanced machine performance. Several methods are disclosed including having one belt flexibly constrained, resulting in a transverse bowing away from the casting centerline due to liquid metal head, with the opposing belt being rigidly constrained and contoured or transversely bowed towards the casting centerline in a configuration that compensates for displacement of the flexibly constrained belt resulting in a uniform transverse cross section. Methods are disclosed including bowing the upper back-up rollers down either by manual adjustment or remote control and at the same time allowing the lower rollers to yield; intentionally rigidizing the upper and/or lower back-up rollers or sections thereof; bowing both sets of back-up rollers in equal and opposite directions, bowing the rollers inward or outward using either manual adjustment or remote control tensioning; bending structural frame members which are in support relationship with rollers, thus maintaining predetermined configurations of rollers in contact with the belts and further including downstream tapering of the casing region.