US SC 2362 Question

I haven't collected US stamps since I was a little kid but for some reason this stamp caught my eye a lot of years back and I put it aside to ask a question about it. And then never got to it till now. It's Sc 2362 and about an inch from the left edge is about a 3/16 inch matte stripe running from top to bottom. The rest of the stamp has a shinier finish. Is that tagging or something else? Sorry but I've tried to get a scan of it but the only way it shows up is at a sharp angle to light.

On my copy of the stamp, the matte stripe appears at the far right of the stamp. It represents the portion of the stamp that is NOT tagged. Presumably, these were block tagged & the block is not always positioned properly.

I see nothing mentioned regarding a tag or any other special marking. Could it be something related to the stamps being released as a booklet?

JLLebbert is correct. The stamps are block tagged. If the block of taggant is properly centered, there will be an untagged area around the perimeter of the stamp. A slight misregistration may leave a wider untagged strip at one side and none on the opposite side. From John's description of his stamp it appears that the tagging was significantly off center.

Thanks for the info. The untagged strip is almost dead center on the stamp. I guess that was what caught my eye originally.