We have observed that thicker than normal LPE bubble garnet films (14–17 μm) have lower coercivity than those of normal thickness (3–5 μm). We have investigated this thickness dependence of 4 film compositions in the SmCaGe garnet system. In thin films, coercivity is dominated by a high coercivity region near the substrate. As the film thickness increases, the coercivity decreases approaching a ’’bulk’’ value. The two portions of the film, with their different properties, produce a linear relationship of coercivity versus reciprocal thickness which should be taken into account when comparing coercivities of LPE garnet films.