Stitch Watermark- Vertical And Horizntal On 1 Stamp??

Ok I found this very strange for a couple reasons- First is I have the same stamp (Nova scotia 8.5 cent) with same horizontal markings in pretty well same position. Both stamps are mint with gum so the lines show easily . However it almost seems as this may be caused by something indenting -- With the first one I left it as possibly the way the sheest were stacked but bow seeing this one it makes me really curious. I'm also wondering if when the paper was being made would there have been the possibility of both vertical and horizontal stitching of the main sheet/ roll of paper. Also since most pics I've ever seen of stitch watermarks were on used or at best no gum examples would they stand out like this on mint copies. First 2 pics show the new find with V&H marks and the bottom pic shows the previous one I found. Any insights greatly appreciated.