SharePoint 2010 introduces the ribbon bar as a central place for all the editing controls, that in earlier versions could be scattered across the page.
When designing custom master pages for SP 2010 you may want to visually integrate the ribbon bar into the design, as is done in the out-of-the box v4.master (wiki & workspaces) and nightandday.master (publishing portal) pages.
To do this, I have documented the size of the different elements, so they can be included in the design.
Continue reading SharePoint 2010 design considerations(3 min read)