Experiments were carried out on a single-roll strip easter to establish the relationship between key process parameters and the as-cast microstructure. In this research we have investigated the influence of the casting temperature, wheel temperature and the composition of an AlMnMg-alloy. The composition of the AlMnMg-alloy is varied with minor additions of Fe, Cr, Mg, and Si. These additions affect the morphology of the intermetallics and the casting temperature affects the size of the intermetallics. The size of the intermetallics becomes smaller with a higher casting temperature. This effect is much stronger for a higher wheel temperature. The equiaxed grain size is affected by casting temperature and wheel temperature. The length of the columnar zone between the alloys is equal when casting at liquidus temperature and varies with a higher casting temperature.