What are overprints, specifically t206's?
 

Read some about the Old /ill counterfeit ones in the past and have seen some on ebay. I assume these are cards which have been printed on twice, correct?

They seem to have brighter colors, are more vivid as well.

How do they affect the value of the card if the image still looks sharp and vivid?

Thx in advance!

You will get better response in the pre-WWII section.

Overprints have an extra printing.

As for value it seems the errors are hot in T206's for now.

Here is a picture of a modern overprint sheet. Sorry for the bad pictures.

oopps, I moved it. Thx for the reply.