This handy grid was rendered in Photoshop using a script.
The picture above links to the full size 512×512 version.
I used it for testing out texture mapping. You know for 3d programs and stuff. Ok, fine… it was to help make clothing for me aah that is my avatar Second Life.
As a reference grid, it has some useful characteristics. It uses color-boundaries rather than drawn lines, for best pixel accuracy. It uses a sort of fractal checkerboard pattern to provide sightlines at different visual resolutions.
Drawing this by hand would be impractical. Fortunately, Photoshop supports scripting in plain old JavaScript. I’ve put the script (and others!) up here. Just download the script and run it from Photoshop’s File/Scripts/Browse… menu.
Of course, it will just draw the same image as above (which is free for anyone to use by the way). But it might be informative to one interested in Photoshop scripting in general, or useful to modify for similar needs.