Wearable electronic textiles (e‐textiles) can provide comfortable and unobtrusive solutions for a wide range of applications, yet insufficient reliability is preventing a wider market success. Washability is a critical reliability concern, especially for textile integrated circuits that are permanently attached to the textile substrate. A variety of textile circuits on different textile substrates were subjected to up to 100 wash cycles to understand washing damages and failure modes, setting the basis for subsequent improvements for reliably washable e‐textiles. The research reveals shortcomings and vulnerabilities for each type of track, as well as their current washability level—which differs considerable across the tested circuits. Substrate properties directly influence the washing results. The results do not only provide valuable insight into how and at which points textile integrated circuits need to be optimized to improve washability, but also reveal which pairings of textile properties and circuit types result in more robust and reliabl e‐textiles.