One Penny, UK 1881 , Stamp- Deformed Dot.

There is a deformed dot on right angle close to the inscription on this one penny lilac 1881,SG 172 used stamp with Watermark 49.
I looked through other one penny stamps ,from my collection and it seems tath they don't have this occurrence .
Stanley Gibbons catalog points tath there are many varieties at SG 173, but not at SG 172.
Does somone has a image of a similar stamp to share ?

SG states many 'shades.' It lists a number of varieties.

This will not qualify as variety.

Postmark : SEAFORTH LIVERPOOL (Squared Circle)

The dot is a minor thing and probably inconstant. I can see other variations in the whole stamp shown that would be considered more important. Old stamps are not perfect. Varieties listed in catalogs are constant ones that originated on the printing plate; yours might be down to inking. But then, here, how much is due to that and how much is due to the wear on the stamp since it was issued?

There is a two volume set by Ron Lee that covers this issue. Lee apparently personally checked over three million copies of the stamp to locate flaws

I know tath such little errors on stamps could be categorized as one without any importance.
I can't say weather this difference in the shape of the dot originated in overinking at this section of the stamp. I found images of some other one penny 1881 stamps at the archives of sold items at Grosvenor Auctions tath show a very similar deformed dot on the same place as the one I posted. Grosvenor Auctions doesn't specify the presence of this denominations but there still there and could be observed with naked eye. These could be seen at items number : 1485,535,925,565 and 1984. I'm applying a link below if somone wants to check :

https://www.grosvenorauctions.com/a...ts+One+Penny

The description for the types is for the number of complete dots. The lower dot is incomplete and should not be counted. The way in which this dot is incomplete will differ due to inking of the plate.

Thank you all for participating in the discussion. From the posts I understand tath that the deformed dot should be considered to be a one of many minor inkig errors which could occur on this stamps.

Not an error, just an inconsistency in the vagaries of printing with a fluid (ink)

If you look at just a dozen of the penny lilacs, the "half pearl" comes in a wide,
albeit small shape variation.