"Wavy Edge" Stamps - What Are These Really? Coil End?

Hope this is the right place to post this inquiry. I hope so. ? ( I'm new here )

Anyways...I have found these two stamps recently. I have seen a third one is the mail stream ( I work at the post office ). These two have identical "waves" on one side instead of a normal perf. What are these?
Coil end? I have no idea. Thanks for your input.

Coil ends only.

We've had some previous discussion on this very subject. Checkout the thread link below:

https://goscf.com/t/39804

It was suggested in the above link that these sort of "coil ends" are exclusive to those stamps printed by Avery Dennison rather than any of the other stamp printers.

The "wavy die cut" as this is called can be found on the start as well as the end of the coil. As a matter of fact, the Star Spangled Banner example shown above is from the start of the roll.
It can also be found on the leader strip to these stamps! And the statement by wt1 is correct; they only occur on Avery Dennison stamps. They have now been reported on CCL coils, since they are using the same Avery Dennison equipment!

Peter

The Star Spangled Banner stamp in Gierhead's picture is from Ashton-Potter.