The hybrid integration of electronics in flexible substrates using fanned-out, wafer-level packaging (FOWLP) has recently gained significant attention, with numerous applications in wearable electronics, foldable displays, robotics, medical implants, and healthcare monitoring. In this study, a fully additive and scalable manufacturing process flow to realize a low-cost, flexible FOWLP system was introduced. Here, the integration of 36 LED chips in a biocompatible polydimethylsiloxane (PDMS) substrate was demonstrated using a stencil-printed silver (Ag) redistribution layer (RDL). The processes for the integration of chips, i.e., chip first (exposed die embedding), chip first (deep embedding with filled valleys) and chip last (RDL first), were implemented, and the corresponding samples were evaluated electrically. The bendability of the samples was also characterized at different bending diameters. Conclusively, it was shown that by using surface-modified PDMS as a flexible substrate and stretchable Ag paste as interconnect, flexible FOWLP can be produced.