Sorry, maybe that is not a good thing to talk about here. I just removed the second picture.
I highly suspected that they were altered stamps when I acquired them. I collected them to see what technique people can do currently. These two examples are the ones that are easier to spot. I guess I'm the only few collecting this kind of stuff. I posted the pictures here not to confuse peopel, just for reference.It seems to me that this topic is too sensitive, I should stop right here.

If the overprint can be wiped completely and undetectedly, that would be very scary. A fellow from APS local club told me few years ago that anything is possible now. He had seen one that he could not tell it's been altered and yet he is an expert on altered stamps.

I see your point. If I post one that even an expert can't tell, that will create a signicant panic on stamp collecting here. I appreciate your advice.

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Sorry, maybe that is not a good thing to talk about here. I just removed the second picture.
I highly suspected that they were altered stamps when I acquired them. I collected them to see what technique people can do currently. These two examples are the ones that are easier to spot. I guess I'm the only few collecting this kind of stuff. I posted the pictures here not to confuse peopel, just for reference.It seems to me that this topic is too sensitive, I should stop right here.

If the overprint can be wiped completely and undetectedly, that would be very scary. A fellow from APS local club told me few years ago that anything is possible now. He had seen one that he could not tell it's been altered and yet he is an expert on altered stamps.

.......

My words might be too strong. We are facing the dilemma of calling collector's attention and help improving techniques for making fakes. My suggestion is totally ignoring these obvious fakes. High quality fakes of the unissued silver yuen (see the note under Scott #984-987) stamps exist. I hate to say it but it seems sooner or later dangerous fake of flying geese without denomination may appear. I do wish they appear as late as possible. Frankly, I condemn those who sell fake stamps on eBay even though the sellers clearly say those are reproductions. We never know where those fake stamps will end up. At the end the hobby gets hurt.

I would not worry about the flying geese without denomination being targeted. We all know how many they exist and it is highly unlikely one would show up on an online auction.

The faint denomination that I took down from the posting is an obvious one, one that the maker could have made it completely undenominated. But again, he or she knows that it would attract too much attention then get removed by Ebay.

BTW, is there a better word to describe stamps like this? They are not fake but altered. Forging stamps or money can be called counterfeiting. Not sure about this.

There is a famous book for this.

I remebered I read this book at the library a while a go. It's a bit old. I'll try to look for newer edition if it exists. Thanks for the info.

Schmid's book is old. Obviously, some newer technologies are not included in there.

There exists even older books (unfortunately the title is not in my head) in the counterfeit detecting topic. For example, the early Shanghai large dragons were studied in the first part of 20th century. Some "private reproductions" back then have become classic reference. If someone would like to put into efforts, I believe the China large dragons are another suitable candidate for counterfeit study. (If one ever pays attention to large dragons, he or she would find that the market has been upset by high quality fakes.)

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My job is related to test engineering, therefore I always look for evidence and proof.

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Below is a very good and yet inexpensive way to detect fraud - remember to hover your mouse on the large picture at the bottom of the page.

http://petapixel.com/2010/03/25/how-photoshop-helped-save-my-dad-from-ebay-fraud/
 
©³¤U³o­Óºô¯¸¤p§ÌÆZ³ßÅwªº. He is a member of the APS.

http://riversidestamps.com/Fakes.shtml

Very interesting sites. Thanks.

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