Although the value of high-density surface electromyography (sEMG) has already been proven in fundamental research and for specific diagnostic questions, there is as yet no broad clinical application. This is partly due to limitations of construction principles and application techniques of conventional electrode array systems. We developed a thin, highly flexible, 2-D multi-electrode sEMG grid, which is manufactured using flexprint techniques. The material used as electrode carrier (Polyimid®, 50µm thick) allows grids to be cut out in any required shape or size. One universal grid version can therefore be used for many applications reducing costs. The reusable electrode grid is attached to the skin using specially prepared double-sided adhesive tape, which allows the selective application of conductive cream only directly below the detection surfaces. To explore the practical possibilities, this technique was applied in single motor unit analysis of the facial musculature. The high mechanical flexibility allowed the electrode grid to follow the skin surface even in areas with very uneven contours, resulting in good electrical connections in the whole recording area. The silver-chloride surfaces of the electrodes and their low electrode-to-skin impedances guaranteed high baseline stability and a low signal noise level. The electrode-to-skin attachment proved to withstand saliva and great tensile forces due to mimic contractions. The inexpensive, universally adaptable and minimally obstructive sensor allows to extend the principal advantages of high-density sEMG to all skeletal muscles accessible from the skin surface and may lay the foundations for more broad clinical application of this non-invasive, 2-D sEMG technique.