Horizontal scanning instruments, such as, atomic force microscopes and scanning laser microscopes, acquire three-dimensional topographic maps of surfaces, at scales ranging from tenths of nanometers to hundreds of millimeters, by measuring elevations along a series of traces scanning a region of the surface. Random and systematic errors may influence parameters calculated from these topographic maps. This work investigates anisotropic artifacts in atomic force microscope and a scanning laser microscope measurements by looking at difference between parameters calculated in the tracing and scanning directions. It is found that horizontal scanning profiling instruments systematically introduce anisotropic measurement artifacts when measuring both isotropic and anisotropic surfaces.