 Bao Shicheng (1775–1885) wrote that baked clay moveable type was "as hard and tough as horn"; experiments show that clay type, after being baked in an oven, becomes hard and difficult to break, such that it remains intact after being dropped from a height of two metres onto a marble floor.The length of clay movable types in China was 1 to 2 centimetres, not 2mm, thus hard as horn.But similar to metal type, ceramic type did not hold Chinese ink well, and had an added disadvantage of uneven matching of the type which could sometimes result from the uneven changes in size of the type during the baking process.