Weird vertex paint pop-in?

Hi y’all,

I’m only just getting into vertex painting, and I have a problem. I want to paint on a completely flat surface, but when I do so the paint gets some pretty ugly pop-in. In fact, the smaller the mesh the closer you need to get before the paint loads. But this doesn’t apply for the more complicated meshes I’m using – in fact, there’s no pop-in at all, near as I can tell.

Is there a way to control this pop-in? Are flat surfaces simply off-limits? I thought the number of vertices might play a role, but I’ve tried several different meshes with no change. As long as they’re flat, it doesn’t matter how many vertices they have.

Because I’m so new to this I’m not sure if this is a bug, or a trivial issue easily solved. I searched for answers and couldn’t find anything, so here I am. Hope someone understands what I’m asking.

Have a cool day!