Why does the Cornish Rex coat feel so different from the Devon Rex wave?

You're mixing up the two breeds' genetics. Cornish Rex has a single gene mutation that removes all guard hairs, leaving only the soft undercoat, which creates that tight, uniform velvety texture. Devon Rex has a different mutation that produces a wavy coat with a mix of guard hairs and undercoat, making it feel more like a lamb's wool with a coarser, less consistent texture. If you're expecting one to feel like the other, you'll be disappointed because they're fundamentally different structures.

Both mutations target different keratin proteins, so the structural difference is literally at the molecular level. I've owned both breeds, and the Cornish feels like fine suede because every hair is the same thin, crimped type, whereas the Devon has a wiry, almost broken texture from the mix of normal and defective hairs. Run your hand from head to tail on a Cornish and you get zero resistance, but a Devon snags your fingers with that uneven wave.

The Cornish Rex lacks guard hairs entirely, so every single hair is soft and fine, giving that smooth, suede-like feel. The Devon Rex has a mix of normal and defective hairs, which creates a coarser, more textured surface, almost like crushed velvet. I noticed this right away when I switched from one breed to the other, the Cornish is uniform and sleek, while the Devon has a noticeable springy or wiry quality.

The genetic mutation behind each breed targets different hair follicle development stages. In Cornish Rex, the defect occurs early, producing only the fine, curly undercoat without any guard hairs, which gives that incredibly soft, suede-like sensation. In Devon Rex, the mutation happens later, resulting in a coat that retains some guard hairs mixed with the undercoat, creating a coarser, crimped texture that feels more like lamb's wool or crushed velvet when you touch it. I remember visiting a breeder who had both, and the contrast was immediate - one felt like a plush toy, the other like a wool scarf.