I have a basic problem. I am modeling a Swan chair. I use the Mirror modifier along the X plane. So I have half the chair. And it doesn’t connect well along the seam, it’s squeezed, see image. I need it so the left and right side of the chair connects seamlessly, I don’t know how to do it. I have all the points along the seam on 0 X, and the subsurf is below mirror in the modifier stack, but still there is a squeezed seam. I’m attaching the blend file as well.
swan-04.blend (468 KB)
Ok, I solved the issue, I noticed I had unnecessary faces on the mirror plane, between left and right side.
Your chair has internal geometry at the mirror plane:
EDIT
Ah, you found the solution yourself!