What I was wondering if free blogs can use that feature.
Hi there,
I'm clear on this.
Many free themes have custom backgrounds.
http://theme.wordpress.com/themes/features/custom-background/
If the theme is coded to allow for a custom background then after you activate it here > Appearance > Themes that feature is found on the > Appearance > Background page.
If you activate the theme and go here > Appearance > Theme Options and that option does not exist, then there is only one possible means of adding a cuatom background and that's by purchasing a custom design upgrade and doing the required CSS editing.
Many free themes have custom headers. http://theme.wordpress.com/themes/features/custom-header/
If the theme is coded to allow for a custom header then after you activate it here > Appearance > Themes that feature is found on the > Appearance > Header page.
If you activate a theme and go here > Appearance > Theme Options and that option does not exist, then there is only one possible means of adding a cuatom background and that's by purchasing a custom design upgrade and doing the required CSS editing.
http://en.support.wordpress.com/custom-design/
http://en.support.wordpress.com/custom-design/editing-css/