The Backgrounds directory is probably the Themes' core compoent.

Inside Backgrounds/ directory you produce background images that are

reused by almost all theme's art works (e.g., Distribution, Websites,

Promotion, etc.).  

The Backgrounds/ directory structure can contain directories to help

you organize the design process. 

    Img/: In this directory is where you store all background images

          (e.g., .png, .jpg, .xpm, etc.).  This directory is required

          by rendering scripts.

    Tpl/: In this directory is where you store all scalable vector

          graphics (e.g., .svg) files. This directory is required by

          rendering scripts.

    Xcf/: In this directory is where you store all Gimp's project

          files (e.g, .xcf). This directory is optional. If you can

          create a beautiful background images using scalable vector

          graphics only, then there is no need to use Gimp to produce

          background images. Of course, you can merge Gimp's power

          with Inkscape's power to produce images based on them.  In

          this last case you need this directory.

Inside Backgrounds/ you can create your vectorial designs using

Inkscape and your background images using Gimp. Later you can export

your background image as png and load it in your vectorial design

using Inkscape's import feautre.  Note that you may need to repeat

this technic for different screen resoluions. In that case you need to

create one file for each screen resolution and do the appropriate

linking inside .svg to .png files.  For example if you need to produce

background images in 800x600 you need to create the following file:

    xcf/800x600.xcf

to produce the background image:

    img/800x600-bg.png

which is loaded in: 

    svg/800x600.svg

to produce the final background image:

    img/800x600.png         

The img/800x600.png background image is produced automatically by

means of rendering scripts.

In other cases, like Anaconda's, it is possible that you need to make

some variations to one background image that don't want to appear on

regular background images of the same resolution. In this case you

need to create a new and specific background image for that art

component.  For example, if you need to produce the background image

used by Anconda (800x600) art works you create the file:

    xcf/800x600-anaconda.xcf

to produce the background image:

    img/800x600-anaconda-bg.png

which is loaded in: 

    svg/800x600-anaconda.svg

to produce the file:

    img/800x600-anaconda.png

The 800x600-anaconda.png file is used by all Anaconda art works

sharing a common 800x600 screen resolution (e.g., Header, Progress,

Splash, Firstboot, etc.). The Anaconda Prompt is indexed to 16 colors

and 640x480 pixels so you need to create a 640x480 background image

for it, and take the color limitation into account when designing it.

Background images without artistic motif are generally used as based

to build the Background images that do contain the theme's artistic

motif. 

Background images are linked (using Inkscape's \textit{import}

feature) inside almost all theme art works. This structure let you

make centralized changes on the visual identity and propagate them

quickly to other areas. 

In this structure you design background images for different screen

resolutions based on theme's artistic motif.