<p>Smart textiles represent a ground breaking advancement in the field of wearable technology, seamlessly integrating sensors and electronic components into fabric structures. Despite notable progress in this area, challenges remain in enhancing skin-friendliness, breathability, and overall comfort, which are crucial for practical applications. In response to these challenges, this study explores the development of flexible, stretchable, and skin-friendly textiles utilizing conductive thermoplastic polyurethane (TPU) filaments. A key aspect of this research involves the implementation of fused deposition modelling (FDM)-based 3D printing technology to fabricate these materials. The study is fundamentally anchored in an in-depth investigation of yarn morphology, which serves as the primary structural unit in textile fabrication. To achieve this, a comprehensive evaluation of three distinct TPU-based conductive filaments was conducted, incorporating analyses of surface morphology, crystallinity, and mechanical properties. Furthermore, a systematic resistive hysteresis testing approach was employed to identify the most optimal filler material. The selected filler’s performance was then thoroughly assessed under varying 3D printing conditions to determine its suitability for smart textile applications. The findings of this study lay a critical foundation for the advancement of 3D-printed conductive filaments, paving the way for next-generation smart textile technologies with improved functionality and wearability.</p> Graphical Abstract <p></p>