A method of continuously casting thin strip by dynamically controlling roll crown comprising the steps of: a. assembling a caster having a pair of counter rotating casting rolls with a nip there between capable of delivering cast strip downwardly from the nip with each casting roll having a casting surface formed by a cylindrical tube of a material selected from a group comprising copper and copper alloy optionally with a coating thereon and having a plurality of longitudinal water flow passages extending through the tube having a thickness of no more than 80 millimeters, the cylindrical tube capable of changing crown of the casting surface with changes in temperature of water flowing through the passages during casting or with changes in casting speed, b. assembling a metal delivery system capable of forming a casting pool supported on the casting surfaces of the casting rolls above the nip with side dams adjacent ends of the nip to confine the casting pool, c. positioning at least one sensor capable of sensing thickness profile of the cast strip downstream of the nip and generating electrical signals indicative of the thickness profile of the cast strip, d. controlling the temperature of the water flowing through the longitudinal water flow passages in the tube thickness, e. counter rotating the casting rolls and varying the speed of the casting rolls with a casting roll drive system, and f. controlling the casting roll drive to vary the speed of rotation of the casting rolls and varying the temperature of the water flow circulated through the water flow passages by a control system responsive to electrical signals received from the sensor to control roll crown of the casting rolls during a casting campaign. a. assembling a caster having a pair of counter rotating casting rolls with a nip there between capable of delivering cast strip downwardly from the nip with each casting roll having a casting surface formed by a cylindrical tube of a material selected from a group comprising copper and copper alloy optionally with a coating thereon and having a plurality of longitudinal water flow passages extending through the tube having a thickness of no more than 80 millimeters, the cylindrical tube capable of changing crown of the casting surface with changes in temperature of water flowing through the passages during casting or with changes in casting speed, b. assembling a metal delivery system capable of forming a casting pool supported on the casting surfaces of the casting rolls above the nip with side dams adjacent ends of the nip to confine the casting pool, c. positioning at least one sensor capable of sensing thickness profile of the cast strip downstream of the nip and generating electrical signals indicative of the thickness profile of the cast strip, d. controlling the temperature of the water flowing through the longitudinal water flow passages in the tube thickness, e. counter rotating the casting rolls and varying the speed of the casting rolls with a casting roll drive system, and f. controlling the casting roll drive to vary the speed of rotation of the casting rolls and varying the temperature of the water flow circulated through the water flow passages by a control system responsive to electrical signals received from the sensor to control roll crown of the casting rolls during a casting campaign.