I must admit that I looked at this when it first appeared, but was in a bit of a rush and didn't respond because I wanted time to study it more and think more about my response. I'm very much in agreement with Pete on this and if anything, it's the outer ring that I find most troublesome. The texture isn't strong enough and much too uneven. At some point the lines appear to radiate straight out from the centre (as at about 4:00 o'clock) whereas in other places (at about 10:00 o'clock) they appear to spiral and the spacing between them is a bit haphazard. The inner circles I can't fault, they work well.
Les