The first time you use the File Browser to view a folder of files, you’ll notice that it takes some time to gather information and build a thumbnail for each image. The next time you browse that folder, the images show up almost instantaneously. The trick? Photoshop saves the thumbnails in a cache—along with file information, ranking, and rotation setting. The cache is saved in a compressed and proprietary format on your local hard drive.
We thought this was all just fine and dandy until our colleague Deke McClelland pointed out two problems. First, if your images are on a network server, having rank and rotation information saved on your local hard drive doesn’t help anyone else who needs to see those images. Second, the cache references a specific folder name, so if you change the name of the folder, all the thumbnails, ranking, and so on, are lost.
Fortunately, Photoshop lets you save a folder’s cache file within the folder itself. To do this, select Export Cache from the File Browser’s popout menu. When the exported cache files (which are called AdobePS7.tb0 and AdobePS7.md0) are present in a folder, Photoshop uses them instead of creating new cache files.
If you later write the folder full of images to a CD, Photoshop can even read the cache off the CD. However, any subsequent changes you make to the rankings or image rotation are only stored in your local cache (not on the CD, as it is read-only).
Purge the Cache. Photoshop builds a cache for every folder you open in the File Browser. If you’re looking at images all day, the cache will grow to take up an enormous amount of hard drive space. That’s why it’s a good idea to empty the cache folder every month or so by selecting Purge Cache from the File Browser’s popout menu. Of course, this will delete all the ranking and rotation settings, too, which could be disastrous, depending on your workflow.