The detachment force of ground, 7-mu m-diameter polyester particles overcoated with clusters of silica having a cluster radius of approximately 100 nm from ceramer substrates with varying Young's moduli has been measured. It was found that the detachment force varied inversely with the Young's modulus of the ceramer. The results are attributed to the role of the silica, acting as asperities on the particles, and the degree of embedment of the particles into the substrate.