Abstract: A method for producing a flexible tooling liner for casting a ceramic core is presented. The method includes the steps of producing a three-dimensional (3D) reference object representative of a ceramic core to be cast, disposing the reference object into a containment vessel configured to receive a liquid flexible tooling material, filling the containment vessel with the liquid tooling material so that the reference object is encapsulated by the liquid tooling material on the surface whose topography is intended to be imparted, allowing the liquid tooling material to cure, and separating the cured flexible tooling along a parting surface into opposing portions and removing the reference the reference object.