Angular Material typography sizing is inconsistent w/ Material spec

[takamori]

Bug, feature request, or proposal:

Angular Material does not use the same typography size ranking as the Material spec.
https://material.io/design/typography/the-type-system.html#type-scale clearly shows Body 1 as larger and darker than Body 2.
https://material.angular.io/guide/typography indicates that body-2 is darker than body-1.

This can be seen in the source code as well. https://github.com/angular/material2/blob/master/src/lib/core/typography/_typography.scss#L24
Similar issues apply to other types of font.

What is the expected behavior?

That it would be consistent w/ spec.

What is the current behavior?

It is ranked in inverse order.

What are the steps to reproduce?

1. View the documentation for the Material spec.
2. View the Angular Material docs.
3. View the corresponding source code.

What is the use-case or motivation for changing an existing behavior?

Consistency.

Which versions of Angular, Material, OS, TypeScript, browsers are affected?

all

Is there anything else we should know?

[crisbeto]

The current typography scale is based on the previous iteration of the Material Design spec.

[jfcere]

I am not an expert in that field but I think the font-size and letter-spacing are also wrong according to Material Design Spec: https://material.io/design/typography/the-type-system.html#type-scale

For example, mat-display-1 has a font-size of 112px while according to MD spec it should be 96px.

Am I wrong? Also I noticed there is no mention about the Overline style...