How to hide/delete underline input Angular Material?

I was playing a bit with the appearance property of mat-form-field and found that if you put a “none” value (or any other unsupported value), you will get clear input.

The code:

  <mat-form-field appearance="none">
    <mat-label>"None" form field</mat-label>
    <input matInput placeholder="Placeholder">
  </mat-form-field>

StackBlitz demo (edited from the official angular demo).

The original example can be found here: Form field appearance variants.

I admit, this is a little bit of a hack.