Answer by Simon_Weaver for Density in Angular Material Design for single buttons only

If you want to do it for all buttons in the component you can do this:

:host {    // this particular example is for icon button    @include mat.icon-button-density(-3);}

This way you are still of course putting it on a 'parent' of the button - but it doesn't require a clumsy explicit wrapper div just to achieve that.

Assumes you're using style encapsulation.