Question: I have an [IKEA desk](https://www.ikea.com/us/en/catalog/products/S49932175/#/S59133593) with a subtle fake wood grain paint layer (black) on the surface. The paint in the area that my mouse moves has worn away leaving a shiny textureless surface that the laser mouse doesn't detect. 

What's the simplest, cheapest, most effective way to re-surface that region (or the whole desk)?

I don't like mouse mats. I'm thinking wallpaper or paint, but I don't know what types of paint will provide the surface required for the laser mouse to accurately detect movement.

Answer: 
Shelf liner (contact paper). Cut it into an oversize mouse pad shape with rounded corners and stick it down. You want it large enough that you aren't snagging the edge with your arm, keyboard, etc. It'll feel like nothing but give your mouse a better view. 

You could use black so it's not so conspicuous, but a bold color pattern might be spiffy. Change it out when it gets polished or worn.
Use fabric. The threads are detectable by the mouse. You can cover the whole top with something like a table cloth, or use a smaller piece in the work area. You say you don't like mouse pads but you're considering something like wallpaper, so I assume the mouse pad thickness is it's main problem, and maybe the issue of keeping it positioned.

Soft fabric, like cotton, will have more friction; something like nylon will have less. 

If you want almost no friction, laminate a piece of cloth. That will also keep the surface from wearing and make it easily cleanable. It will be cardstock thickness. Something the size of a mouse pad or place mat can be laminated in readily available heat laminators, or you can use adhesive laminating pockets that don't require heat. A matte lamination film will probably work better than a glossy film for mouse purposes.

You could also print out a custom pattern on paper, as Harper suggested, and laminate it to give it a longer life.

An area-sized piece can be stuck to the desktop with a temporary adhesive so that it doesn't move around.

Note that if you're going to laminate cloth (or a paper pattern) and stick it to the desktop, you're essentially making your own shelf liner, so isherwood's idea is a lot simpler. I'd use my idea instead only if you were going with a table cloth or wanted a material or pattern that wasn't available in a ready-made shelf liner.