What Constitutes An Overprint Variety?

I have been puzzling with this question, particularly when looking at some of the overprints from African countries. I've posted a scan of my Ghana overprint collection for your thoughts and comments. Which do you see as varieties and which as the same?

Varities can be many things. But using your examples above the size of the block height & width may be different. The color of the ink used. The spacing between the block & the new value, the spacing between the numbers, minor ommissions like missing block or new value. Also if there is a typeset varience in the letter or numbers.

Varieties over simplified. You can call it a Variety if it is repeated on more than 1 sheet or 1 stamp. Otherwise it is normally called an error.
Remember I did say Oversimplified!

Thank you for your thoughts and opinions. I appreciate them. Let me try to explain what I'm pondering at the moment.

With the two stamps below, ignoring the fact that the second overprint has missed the value, the overprints appear to be different. The differences appear to be:

• the first stamp has a splodge on the lower end of the stroke through the "C"


• the digits of the "20.00" are not alligned in the second stamp while they are in the first


• the zeroes, particularly after the decimal point, are thinner at the top and bottom in the second stamp

Because of these differences I'd call them different varieties.

Then there are the stamps below, this time joined together. Differences:

• different font on the "2" to the preceding examples


• again, a different alignment of the digits


• thew first one has a hole in the blot out block

Hence, I'd call them different varieties.


Then there are these, below, with a thicker print. Do you see where I'm going?

There are more stamps of the same type with similar differences as on the page in the first post.

Am I being too nit-picky or are these genuine varieties??

I'd say there is 6 different varieties you have.
I've 2 thoughts.
First, was this overprinting done with such poor oversight & quality control that every position on the original mint sheet may have a different variety. That could mean between 24-100 different variations could be out there, depending on the size of the original sheet. Then if all are different would any philatelic group considered them easily as important.

Second, consider source, Ghana, even if there only the 6 varieties as shown above would they be in demand. It's not from western Europe or North America nor China & Japan, even Australia as examples where such variations would be considered important.

A complete sheet of overprinted stamps would be needed to ascertain how many varieties do excess. But then there is a the possibility of multiple devices that created the overprint & from multiple locations.

Ultimately someone needs to do this, why not you!
If collectors never looked into these varieties none would ever be listed.