What are "Wheel Marks"?

Submitted by JonSullivan on Tue, 02/03/2015 - 07:24

Here is an excellent article on the subject, put out by NGC. It will describe in detail what they are, and how to detect them.

Comprehensive Error-Variety Checklist

Submitted by JonSullivan on Sat, 05/30/2015 - 13:52

Comprehensive Error-Variety Checklist


Compiled by Mike Diamond



This checklist is my attempt to compile a comprehensive listing of all known variety and error types, subtypes, and associated effects.