How to avoid gaps between 2D physics objects?

Here I have a project with some 2D physics blocks (objects with a non-kinematic Rigidbody 2D component). As you can see, they have these gaps between them and the ground/other objects.

You may also be able to see from this image that I’ve shrunken their colliders. As I was doing this, I found that even if I could close the gap between the blocks, a gap would remain between the blocks and the ground. If I shrink the colliders enough for there not to be a gap between them and the ground, then they are inside each other.

This makes me think there’s a “skin” thickness setting or something on the physics, but I can’t find any for 2D physics. I’ve tried adjusting the mass and gravity. Neither fix it, though high gravity makes everything jitter. How can I best solve this problem? Thanks!

Just in case someone stumble upon this: Decrease the ‘Pixels per Unit’ property on your textures. This will make Unity show sprites bigger and those little gaps we’ll be filled/unnoticeable.

Don’t forget to adjust the gravity accordingly. (menu: Edit > Project Settings > Physics 2D)

I’m using Pixel Per Unit: 1 and Gravity: -981

Just in case some more people stumble upon this:

The gap is determined by this value.
Changing it to 0.0001 makes the gap unnoticeable, but may also cause some collision wonkiness.