IEC 62899-503-3:2021(E) specifies a measuring method of contact resistance for printed thin film transistors (TFTs) by the transfer length method (TLM). The method requires the fabrication of a test element group (TEG) with varying channel length (L) between source and drain electrodes. The method is intended for quality assessment of TFT electrode contacts and is suited for determining whether the contact resistance lies within a desired range.