The archive interface makes it easy for users to look at your content and make a quick assessment of the sort of posts you share. No matter what the theme you use for your Tumblr page, your archive is always the same: a grey header with the name of your blog and a basic navigation interface, with all your posts clustered and set to fill most of the screen. Like the dashboard, the archive uses endless scrolling by loading more posts when you reach the bottom of the page.
Most of Tumblr is sequential in a reverse chronological order: a single stream of content, with the newest content on top and the oldest content on the bottom. This holds true on the dashboard, on the tumblelog, on every tag page and on nearly every Tumblr theme -- except for the archives. Clustered posts are the standard for Tumblr archives.
The Tumblr Archive
The archive shows posts in the reverse chronological order, just like the rest of Tumblr. If you hover over a post, it will display when it was posted and how many notes it has. Photos are scaled down to thumbnails, while text posts are displayed in a square about 120 pixels around. Photosets only show the first image in the set. Audio and video posts are denoted with a play icon, but cannot be played from the archive.
Navigating the Archive
Every month in the archive is noted by a header. For bloggers who update infrequently, this is more noticeable than the archives of users who post frequently. You can jump to a month in the archive by selecting it from the drop-down menu in the upper right corner of the screen, or appending the URL with the year and month, such as username.tumblr.com/archive/2011/10. You can search posts using the "search" function but the results open in the Tumblr user's regular layout, not the archive layout.
Some Tumblr themes are designed to create a gird or cluster of posts, rather than the standard two-column stream layout. These themes are available from the customization page (Tumblr.com/customize) and are better suited for image-based blogs. Like the archive, it helps make a quick first impression on visitors. Examples of cluster themes available from the Theme interface on the customization page include Astronaut, Photo Stack, Cavalcade, Chunky and Cargo.