I needed just a few more centimeters of crown molding, so I modeled this instead of buying 2m more. But, if you scale it on one axis, you could print your own, entire moldings. 'Cuz you fancy, huh?

HIGHLY recommended to use adaptive layer heights in PrusaSlicer (see sample 3MF) and 0.1mm layer heights as the basis, and a relatively high quality setting, so that 0.1 is the minimum layer, and some are 0.07 even. That way, you won't have layer lines, at least, after you paint, you should be fine. These are almost IDENTICAL to the crown moldings I bought, I can hardly tell which are the 3D printed ones.

(I fixed the extra horizontal line in the model, so the ones in the picture are less perfect than the model itself)

Have fun!

BTW, If you want more things you didn't know you could print, here's a list of 50+ similar items: