Magnetization and domain structure of thin cobalt wedges on textured Au substrates were studied by scanning electron microscopy with polarization analysis (SEMPA). In the thickness regime with perpendicular magnetization, as-grown films contain small domains with diameter between 0.3 and 1.5μm. The small size is connected to the morphology of the film, resulting from the textured nature of the Au substrate. Applying a magnetic field gives a distinct dependence of measured polarization on film thickness, most likely caused by variations in coercivity. Results are compared with those obtained for similar films on single crystal Au substrates, in view of the relation between magnetic properties and morphology.