On a family vacation at Hilton Head, South Carolina about 10 years ago I bought a bottle opener just like this one. My dad wanted one too, but unfortunately it was the last one in the store and the island. This is a perfect, almost stereotypical, scenario requiring 3D printing: the need for replicating a unique object. It also seemed like a good beginner CAD project, so I set out to have one printed for my dad. I started with a rectangular block and took the intersection of a projected shape in all three dimensions. The fin shape was drawn by hand as a spline. The other two dimensions were an isosceles triangle (projected from the back to the front) and an oval (projected from the bottom to the top). I uploaded the STL model and had it printed in stainless steel. Now, thanks to 3D printing, a once rare object is available to anyone.
When I first got it I was worried it would break, but I've opened bottles with it no problem. The fin shape of this one is a little different from the one I was replicating because I drew it by hand. The tip of the fin is thicker than the original because of printing limitations, but no worries it still looks amazing. Finally, the striped pattern comes from the layer resolution of the 3D printer. I think it looks cool because it clearly sets the bottle opener apart as being 3D printed. I gave it to my dad, and he loves it!