Second review of these hooks, because I was happy to see a size "6" added to the lineup. Again, these are very, very nice hooks. The size-by-number is completely arbitrary. I've now tied on and caught fish on the 12, 10, and 8. See other comments for remarks on size. I was hoping the "6" would be a jump in size with the same geometry, but it isn't. It has nearly the identical hook gap, shank to point, as the "8".
measurements for the 8: length bend to eye: 1.09", gap shank to point (inside) 0.35", wire diameter: 0.033"
measurements for the 6: length bend to eye: 1.18", gap shank to point (inside) 0.38", wire diameter: 0.041"
so the 6 is basically a little longer with heavier wire but the same gap as the 6. Wouldn't it be great if there was some sort of standardization of gap sizes in fly hooks? I'm not old but I do remember when pretty much across the board a 6 was a 6, a 12 was a 12, a 16 was a 16, etc. Aside from the size weirdness, these are excellent hooks.