I used to have one of those plastic floor protectors from IKEA for beneath my desk chair, but to be honest, those things are ugly, dirt gathers under it, and they are generally bleh. So I decided to make a mat for my desk area. Back in February I found the really cheap bathroom mats in lovely colours. They can be washed in the machine, are rubber-backed thus won’t slip when I move around on my chair, and can easily be cut and hand sewn with a big, sharp leather needle. I went for a leather one, because I used sturdy DIY tape to glue the mat pieces together and thus had to sew through the material.
I cut off the rounded edges to have straight angles.
I got some broad black cotton webbing/tape off eBay, which was advertised for horses but was exactly what I needed, which would hold the mats together on the top and provide a frame for the colours.
On the back the joints are stabilised by the aforementioned tape, and the edges are bound by the tape.
Here it is, and it has been giving me great service for a few months now. I finished it in July/August and it cleans easily. A unique rug for very little money. Voilà!