Used shark skin for handle/grip on a Selfbow a few years back. It's very durable, but has a scratchy feel. It has a very tactile grain that goes in one direction. It feels a great deal like sandpaper, even after sanding it down.
It's very tough stuff, and might make a good stiff backing, but I was disappointed with the look of it. Ultimately, it turned out grey and unappealing.
To be sure, it's tough-just not something that catches the eye. Good luck!