It says in the technical datasheet of Easy Composistes out-of-autoclave Prepreg XPREG XC110, that for curing the "minimum vacuum pressure is 10mbar". This is a pretty low value. There are many vacuum pumps that can only achieve 50mbar, for example.

So my question basically is: why so low? To reduce the probability for pinholes? Because the relative gain in pressure when going from a 50mbar vacuum pump to a 10mbar vacuum pump is very small when you compare it to the outside pressure of a thousand mbar (well: 960mbar where I live).