This sheath was designed for a 19cm Oneida chef's knife. A raft or brim is recommended for successful printing, as the base of the model is very narrow (I used a 10mm brim). I printed it at 0.2mm resolution, but it should be fine at 0.3mm to speed up printing.

I used a pen to put registration marks every cm along the blade, as well as a baseline. Then came lots of measuring with digital calipers to get cross sections, and lots of lofting in Fusion 360. I printed the first and last 5cm of the model to check the fit, but still was surprised when the final print fit perfectly 8-)

I didn't bother rounding any edges as it's going to sit in a drawer out of sight.