For what it's worth for those who don't checker I think the 3 1/2 and 2 Brad is referring to is the length of the diamonds to the width, as in a ratio of 3 1/2"X1", and 2"X1" and the 90 degrees is the included angle of the "V" groove of the checkering as opposed to the 60 degree angle used in many early doubles having "flat" or unpointed checkering that didn't come tp a peaked diamond. Am I asumming right Brad? I certainly didn't mean to snatch a thread from the Master!!!! Lee.