Hey! Sorry if some terms aren’t the correct ones, I’m still learning.
When I use the weight paint brush it goes through my mesh, for example I paint at the clavicle and it adds weights to the back as well. My mesh has no inner faces, I already tried changing limit selection to visible on/off and changed the brush size, it didn’t help.
Painting at the clavicle:
And it somehow adds weights to the back as well:
I hope someone can help me :’)