How Do You Identify The 3 Cent Special Printing.

I took this picture from Robert Siegel how do you Determine the special printing from the rest?This one is the special printing. I don't know what to look fore

Kingstonstamper, in my Scott catalog it says that the Special Printing is extremely difficult to determine.
Have you tried Stampsmarter? That is usually the place to go to for these stamps!

Peter

I have tried a few places but no luck they list the # and show the picture. 1847 sight shows the ones that I can Identify and gives the # but no real good hey this is what to look for. I am sure there is a sight out there I just haven't come across it yet. If I cant Give it a solid I identification by the end of the week I will probably bring it to the Show and have some of the people there take a look at it.It has the blue color just needing the Info.

Two keys are a very sharp clear impression and very thin bright white paper. special printings almost glow when you hold them up to the light.