Henry Vi Groat Mystery Die Lines

[Nicholas]

I have a H6 Calais Groat with mysterious die lines on the obverse. Circular rings behind the portrait. http://s1322.photobucket.com/user/2tearsinabucket1/media/image_zps4e0dde41.jpg.html?sort=9&o=10

Any thoughts?

[Coinery]

I can't see anything on my phone but, the grinding back of old die stock, can leave underlying marks, could it be that?

Rob's the man, he's got coins even with traces of devices left behind!

[Rob]

Could be guide lines for the engraver. The circle appears to touch the tips of the lis on the tressure. Wire lines are commonly seen on hammered coins where there is no beaded circle present at that point. so for example. this type 3 shilling reverse has one to tell the engraver where to place the letter bases.

Edited August 12, 2013 by Rob

[TomGoodheart]

I agree with Rob. Probably guide marks for the design. Similar marks appear to be present on this one of Richard III: