designed to produce the outer contour of the finished core the fired core is then formed exactly as described in example 1 above ten core test bars having a cross section thickness of 0 450 u2033 produced using example 2 exhibited an average pitch shrinkage of 0 43 a core having a cross section thickness of 1 7 u2033 produced using example 2 exhibited a pitch shrinkage of 0 5 the same core produced using no chill and the same material as in example 2 exhibited a pitch shrinkage of 1 6 another embodiment is comprised of a ceramic chill and skin both produced by pouring a liquid ceramic slurry into molds and subjected to sequential heat treatments in this case the binder for the chill is the same as that described above for the skin the ceramic powders are comprised of the following formulation dry blend wt u2212 325 mesh zircon 18 80 u2212 200 mesh fused silica minsil 40 17 28 10 micron fused silica 15 24 u2212 70 100 mesh fused silica 48 67 the binder is mixed with the powders in a 4 1 weight ratio of powders to binder a desired chill shape is formed by mixing the ceramic slurry with a catalyst in the manner described in example one pouring or injecting the ceramic binder system into an aluminum die.