Wet-felting: raw wool is carded (combed to align fibers), laid into a pattern or stuffed into a mold, then rolled with hot soapy water for 2–6 hours. The agitation causes wool fibers to interlock permanently — no stitching, no glue, no backing fabric. For cat caves and larger objects, the shape is formed around a resist (often a plastic mold) and felted from both sides. When dry, the felt is brushed, trimmed, and sometimes decorated with needle-felted details. Every artisan develops a “hand” — experienced felters can tell a beginner from a master by density alone.