Add more layouts to use at upfront


I would like the option to make another layout eg: 1600px wide, but I cannot find how.

I edited these files:

Panino: main-header.php (global-regions/main-header.php)

Upfront: class_upfront_grid.php (library/class_upfront_grid.php)

where I added lgdesktop (Large Desktop, 1560px)

I beleive there are more, but I cannot find

Please advise