For TTS backgrounds, go here: http://www.theskjaldborg.com/index.php?threads/360-180-panoramic-backgrounds-for-tts.12361/ Any cool models or textures you find should be posted here.
Here's a green leather texture that looks very nice on playing tables that can use custom images. It works well as a generic playing surface, but can pass for "grass" with most tabletop strategy games like Battletech, Warhammer, etc. Image is 5,000 x 3,333
