Theme Folder Widget
For the Theme Folder Widget (dashThemeDir), enter the name of the folder (not the path) that contains your background images. This can be any folder inside img/BoxPressThemes that has five files named BannerImage.png, BannerTexture.png, BodyImage.png, BodyTexture.png, and FooterImage.png. To make a new theme, just make a new folder and create (or add) four image files with these same five names. Make sure they all end with png. Even if they are other formats, use the png extension.
Managing your background images and textures in the Finder by simply renaming and moving files is a great convenience because you can preview images easily in the Finder. You can keep old images in your Theme Folders simply by adding to their names—e.g., by changing BodyTexture.png to BodyTexture_OLD.png.