Few people have gotten close enough to a shark to pet it. If you could run your hand from a shark’s head to its tail—not that you should—it would feel smooth, almost like suede. Reverse direction and it’s rough like sandpaper. Viewed under a microscope, shark skin is composed of ribbed, dragonesque scales layered over each other like shingles on a roof. These structures, called dermal denticles, are more like teeth than skin
Nah, you’re wrong. Sharks are silky smooth in all directions.
https://www.smithsonianmag.com/innovation/shark-skin-inspired-materials-have-a-long-way-to-go-before-they-work-like-the-real-thing-180980973/
The link you posted says sharks are smooth as the finest silk in every direction.
You sound like you are trying to trick people into getting their skin rasped off by sharks.
https://www.tumblr.com/world-heritage-posts/654918860179406848/slangwang-bransonreese-crystallotusfr