Posted By:
DDPart of the issue is the graders should know enough to see, or at least look for your corner flip, or other alterations. As mentioned previously in this post, comic book graders (CGC) clearly indicate on the slab when a comic has been restored.
This information does not necessarily come from the person submitting the book. There are knowledgable people who grade the books, and they have the technology to identify when a comic has been restored.
Regardless of how some people may restore cards and try to pass them as authentic, it is not foolproof. The grading companies have to want to look for it, uniformly in every card, in order to be accurate about the grades, and any level of restoration. The technology clearly exists to do this. Grading is more than measuring centering and dimensions with a micrometer, and determining to what level a cards' corners are sharp. Even with these basic components of grading, there are still flaws. Until something is done, the restored cards ending up in slabs will continue.