A month ago, seeing Stephen Birks’ Mystic Mountain battle mat, and seeing that Inked Gaming just happened to have a promo where international shipping fees were waived, I did a version of my Battle-Grid: Radius Alpha with a full circular grid as well and put in a custom 36″ x 36″ order. It arrived and it’s marvelous. (And perhaps bigger than I needed!)
Here is the image file with the background (7 Mb), as well as black and white overlays if you wish to design your own.
Black (PDF)
White (PDF)