eyebrows

When your sculpting a human head do you have to sculpt eyebrows or leave if for particle hair system so that the final image looks realistic ?

do you need to do both
i want my sculpt to be animatable and realistic and also ready for 3d printing
(i know sculpted hair , eyebrows, eyelashes should be made in mesh or order to be printed)

I think you answered yourself, if your goal is to be ready for 3D printing, if you want 3D printed eyebrows, you’ll have to make them sculpted on the character sculpt.

Now if you don’t go the 3D printing route, for animation, you would need to retopo first your sculpt, as you can’t really animate a million poly character, at least in Blender without serious performance issues. And from there, both particle hair or just texture would work to make eye brows.