The 4th PSIS on Soft Matter "Faces of Soft Matter" 2026 is intended to integrate diverse theoretical and experimental approaches, with both intrinsic and extrinsic factors influencing soft matter systems being considered. In this edition, the development of a unified interdisciplinary perspective is pursued, and new directions in scientific research are sought to be revealed. The “Young 4 Soft Matter” DAY is designed to provide support to early-career researchers. A platform is offered for the presentation of research results, the exchange of knowledge and experiences, and the establishment of collaborations within the soft matter community. During this session, participants are given the opportunity for their achievements to be presented through talks and posters. Directors of PSIS on Soft Matter Aleksandra Drozd-Rzoska & Samo Kralj