Type Matters: Trapped in a box

Imagine being crammed into a very small space. It's not very comfortable is it, having your body contorted and restricted as you have to fold up your limbs to fit. It becomes quite difficult to breathe too.
Not good.

Very much the same applies to type, believe it or not. It may not be an actual living organism, but it hates being hemmed in by unforgiving boundaries. If you need to put it into a box, give it some breathing space and allow a generous but proportionate margin.