High quality Kanthal A1 wire by Twisted Messes is composed of 20.5% chromium, 5.8% aluminium and an iron balance. Kanthal A1 is stronger than Nichrome80 so a bit easier to work with below 38g. It also has a thicker oxide layer compared to Nichrome80, so it is less likely to cause hot-spots when dry-firing a coil.

27-28g is used for core wires of multi-strand Claptons like Alien Claptons and the thinner gauges (36-40g) are for Clapton coils, multi-strand twisting or to add a bit of colour to your coil-art.