This series of Experiments with Shaders explores several variations of a simple fragment shader that are used to provide colourful, at times rather psychedelic, backgrounds for performances. The shader kernel is based on WyldAnimal's 2DShader-0001.fsh, but it now bears very little resemblance to the original although it still uses the same basic algorithm and it produces similar output when used with its default parameterisation. Some initial experiments soon showed that it was an extremely tedious excercise to generate more than a small number of variations by just editing the fragment shaders and scene files using them by hand. This being especialy so when improvements were being retro-fitted into any older versions. To overcome this the approach taken was to create a generic kernel that could be tailored using a number of parameters. The initial intension was to use a scheme in which the kernel was used via an include directive in a shader fragment file of the form #define parameter1 value #define parameter2 value etc. #include TheEmu-A.fsh-kernel but although #define is by the shader language #include is not, so the kernel and its tailoring parameters have to be in a single file. Rather than maintain several copies of the sahder kernel I use I use a simple script file to concatenate it with each set of parameters to create the set of .fsh files and .scn files using them. Refer to comments in the script file and in the shader kernel for how to use them, but note that the details may change significantly as the system used to generate the scenes matures. A more formal guide may be prepared at a later date.