A compromise — #21 of 31 Alpaca ranks #21 of 31 fabrics for chafe resistance. It is a middling fabric for this. Ranked with a smooth-fibre bonus plus low weight and breathability. The top pick is Silk.
Alpaca measures 58/100 for breathability, 14% moisture regain, 88/100 warmth, at 220 gsm. Chafe resistance rewards a smooth, light surface: Alpaca has more surface texture at 220 gsm.