Simple embossing / debossing die of the Bridge 4 emblem. Bridge 4 is an awesome group of people from the Stormlight Archive book series by Brandon Sanderson. (if you haven't: read it! it's awesome!)

I printed in PLA+ with 100% infill, sanded the top to make it smooth, and then used it between to stamp the design into (faux) leather, wedged between two scraps of plywood in my vise.