The following is an example of Crimson Roman set at a font size of 16 pixels and a line height of 24 pixels. I created a light blue baseline pattern that repats every 24 pixels and lines up pefectly with the type.
Aenean lacinia bibendum nulla sed consectetur. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Nullam id dolor id nibh ultricies vehicula ut id elit. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nulla vitae elit libero, a pharetra augue.
Here's Crimson Semibold set at the same font size and line height, with the same baseline background pattern.
Aenean lacinia bibendum nulla sed consectetur. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Nullam id dolor id nibh ultricies vehicula ut id elit. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nulla vitae elit libero, a pharetra augue.
And here's Crimson Bold again set at the same font size and line height, with the same baseline background pattern.
Aenean lacinia bibendum nulla sed consectetur. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Nullam id dolor id nibh ultricies vehicula ut id elit. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nulla vitae elit libero, a pharetra augue.
If your browser displays the fonts the same way as mine, you'll see that the different weights align vertially to the same baseline. This is the desired behavior, and when you combine different cuts of Crimson within the same paragraph, the line height remains consistent, like so:
Aenean lacinia bibendum nulla sed consectetur. Fusce dapibus, tellus ac cursus commodo, tortor mauris condimentum nibh, ut fermentum massa justo sit amet risus. Nullam id dolor id nibh ultricies vehicula ut id elit. Cum sociis natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Nulla vitae elit libero, a pharetra augue.
Likewise, if Crimson is styled similar to a button with 12px padding around each word, the linespacing appears to be consistent.
I'm assuming all of the above displays the same cross-platform, but in case it doesn't, here's a screenshot of how this page appears in Google Chrome on OS X.
