Debian Wheezy boot splash screens

Grub wallpaper and resolution can be changed by editing
  /etc/default/grub
and running:
 update-grub

The boot splash screen can be enabled by editing
  /etc/default/grub
and adding "splash" to the Grub command line:
  GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
and running:
  update-grub

The splash will not appear unless a splash package is installed.
The only package available in standard repositories is plymouth:
  apt-get install plymouth-x11

Other external packages:
 Bootsplash - original kernel space implementation
 Usplash - designed to replace Bootsplash, implemented in User space
 Xsplash - used in Ubuntu Karmic to take over from Usplash
 Plymouth - designed to replace Usplash+Xsplash
 Splashy - a Debian project, last updated in 2008, implements splash using framebuffers in user space, not  compatible with startup system in Wheezy.
 Fbsplash - a Gentoo splash implementation, not available for Debian


Once installed, the plymouth splash theme is updated using:
  plymouth-set-default-theme

*When plymouth is removed, it still leaves the theme embedded in initrd.  To complete the removal of plymouth boot splash, update the initrd image:
  update-initramfs

**Wheezy contains a package called "startupmanager" which is described as providing an easy to use interface to update some settings for grub & splash screens - but it does not give correct resolutions and only  has a tick-box to enable or disable splash screen.  startupmanager corrupts /etc/grub.d/00_header by hard-coding a resolution that will prevent GRUB_GFXMODE from working in /etc/default/grub.

***Screen corruption occurs if using Slim display manager when Plymouth is installed.