I made this flight model for my dart arrows, slightly inspired by https://www.thingiverse.com/thing:3453402 (using the same height). The dimensions are
length: 42mm
width: 32mm
height: 0.3mm

Tested on different arrows and seems to be working fine, but I recommend some glue to keep the wings together.

The flighs are easy to personalize with a name or logo using e.g. Tinkercard (check the picture with the white and green flights).

Printed on a Prusa MK3S, 0.1mm detail and 15% infill. No brim or support.