I liked the idea of watsdesign's business card holder, but when I printed it, the 0.5mm-thick sides were too thin; they warped and buckled a bit. So I remixed it by simply thickening all the sides to 1.0mm. I also found it was just a little too small to fit my cards, so I expanded it 1mm. Finally, for a little flourish, I added a few rounded corners.Doesn't need support or anything else, though I did use a brim since it has a fairly small amount of surface area on the print bed. Be careful removing it from the print bed though; since the bottom is so thin, it can be easy (depending on print quality) to break off the bottom in the process.