I was testing a bit with different cores and layers of carbon under the core and one of my friends asked me what causes the core to print through to the carbon. And I honestly don't know the cause. This was Lantor Soric core in the example below.

I know and expect that it happens when using only a single layer... but the why is a mystery to me. Is it just that the core compresses more than the carbon under vacuum and moves the weave a little bit?
Pic for an example: