




Ok, think I have found the answer, all the above count as perpendicular corners. The image below shows the rounded corners.

None of the stamps in the top two rows have perpendicular corners. They are all Scott 4236-39.
I can see where the Scott listing can be confusing. It could be assumed that all stamps listed below the "perpendicular corners" notation have perpendicular corners until reaching the "rounded corners" notation. But that isn't the case. Only Scott 4232-35 have perpendicular corners, and, as seen in your single perf 9.5 stamp, they occur in all four corners. I don't know why Scott even included the "perpendicular corners" note because 4232-35 can be distinguished from other sets of these designs by die-cut gauge alone.
The stamps with die cut gauge 11 with rounded corners are from large roll coils of 3000 and 10000 and are Scott 4244-47. All four corners are rounded. Mint stamps are on backing paper that is taller than the stamps and there are gaps between the stamps on the coil. Here's a scan of those stamps..
BTW, the 2026 edition of the Scott US Specialized includes illustrations of all of the varieties of this set.
@tommcf, thank you for the confirmation, definitely misleading in Scott, as normally previous remarks etc apply until countermanded. I have just purchased a mint set of those with rounded corners and will now seek out used copies.
Thank you again.
Let me add that, depending on how the rolls are cut, Scott 4240-43 could also display perpendicular corners. That set can also be identified by die-cut gauge alone. But Scott 4236-39 definitely do not have perpendicular corners.
Here is a close up of the rounded corner stamp, a bit easier to see than the above.


I am having a bit of trouble in correctly identifying the perf 11 varieties with rounded as opposed to perpendicular corners. Scott helpfully does not show the difference or even which corners.
From the scan below I think that in the top row the 3rd. and 5th. stamps are perpendicular in the bottom left corner.
In the bottom row I think it is 1, 3 and 7 that are perpendicular.

But none are like the perpendicular corners on this 9.5 perf one.

I would be grateful for any input and before someone mentions it, yes I'm aware of the extra white stripe on the moon one. It was apparently an error not of the artists making.

re: 2008 Flag stamps
Ok, think I have found the answer, all the above count as perpendicular corners. The image below shows the rounded corners.

re: 2008 Flag stamps
None of the stamps in the top two rows have perpendicular corners. They are all Scott 4236-39.
I can see where the Scott listing can be confusing. It could be assumed that all stamps listed below the "perpendicular corners" notation have perpendicular corners until reaching the "rounded corners" notation. But that isn't the case. Only Scott 4232-35 have perpendicular corners, and, as seen in your single perf 9.5 stamp, they occur in all four corners. I don't know why Scott even included the "perpendicular corners" note because 4232-35 can be distinguished from other sets of these designs by die-cut gauge alone.
The stamps with die cut gauge 11 with rounded corners are from large roll coils of 3000 and 10000 and are Scott 4244-47. All four corners are rounded. Mint stamps are on backing paper that is taller than the stamps and there are gaps between the stamps on the coil. Here's a scan of those stamps..
BTW, the 2026 edition of the Scott US Specialized includes illustrations of all of the varieties of this set.

re: 2008 Flag stamps
@tommcf, thank you for the confirmation, definitely misleading in Scott, as normally previous remarks etc apply until countermanded. I have just purchased a mint set of those with rounded corners and will now seek out used copies.
Thank you again.
re: 2008 Flag stamps
Let me add that, depending on how the rolls are cut, Scott 4240-43 could also display perpendicular corners. That set can also be identified by die-cut gauge alone. But Scott 4236-39 definitely do not have perpendicular corners.

re: 2008 Flag stamps
Here is a close up of the rounded corner stamp, a bit easier to see than the above.
