What causes this weird clavicle cut?

Here's how it looks on edit and wireframe mode:

  • adrian replied

    It looks like you have flipped normals. Every face has an inside and an outside, you get some wired things happening if you have faces inside out.

    In edit mode select all the faces with A, then press SHIFT + N to recalculate the normal direction.

  • gabrieljim replied

    That was exactly what has happening, I was so confused!

    Thanks once again Adrian