One of the most common questions stamp collectors have regarding varieties and errors is: is it constant or just happened to a few stamps?
Well, what a better way to answer this than having a specimen or proof with the variety/error?!?!?!
Here you can see a specimen of Scott C159 with the variety of the hut over the “T” of Costa.
This error was first found by Enrique Bialikamien.
Lets take a closer look…
For this kind of studies, we recommend the following tools: