These images are copyrighted (c)2015 by Robert Brunck
You can contact Bob here.
This page was updated on 03-02-2016
This is an 18 step greyscale from [R,G,B] of [0,0,0] to [255,255,255] in increments
of [15,15,15]. For best viewing on images you should adjust your screen brightness
and contrast to be able to see the changes of all 18 grey shades ...