Posted By:
DavidI don't wish go too deeply in identification of alterations, but most alterations (even sophisitacted alteration) can be identified by the collector who is motivated to learn how to identify. Simple and inexpensive methods like using a blacklight, checking opacitiy and holding the item at angle to a light source to check gloss, are highly effective. Somtimes inpainting can literally be felt by running one's fingertip across the surface. In some cases more advanced methods like using a microscope or infrared viewer are neccesary, but even these methods are used by highly motivated collectors (many fine art painting collectors own a infrared viewer).
The vast majority of non-trimming alterations are not going to be professional restorations of ten thousand dollar Babe Ruths, but some joker coloring in the border on a $10 1963 or 1971 Topps.
As I said before, while it's great and encouraged to get second opinions from experts and card graders, it's the collector's responsibility to do his or her (hi, Julie) homework and examination. Most collectors are not interested in learing about authentication, but that is their issue not someone else's.