symmetry basics

hi guys, i have a quick question about the mirror modifier, probs symmetry in blender in general.
i traced the outline of an aluminium extrusion profile and used the mirror modifier on two or three axis of symmetry. problem is that my model then shows some kind of differently reflective seam along the joint. this doesn’t go away by applying material or texture. i even tried modelling differently. does anyone have any advice?


Delete internal faces where two sides meet.

The modifier order also matters. Mirror above surdivision surface modifier for it to mirror the control cage first and then subdivide that.

Always include an example .blend with the questions, and don’t scale/crop screenshots. Window menu -> save screenshot in Blender saves just the Blender interface.

thanks a lot guys, everything working now :)!