POPSEWING® Epsom Leather Inspired Calvi Card Holder DIY KitIs It Worth It? There are plenty of card holder to choose from, if you want those unique pieces, get a good look at this DIY Calvi Card Holder Leather Kit! As anyone who hates carrying too much, card holders are a great option. They're small, sleek and hold just the essentials. The inspired Calvi card holder kit is constructed like origami, with a simple folded design out of a single piece of leather. No logos or loud branding, it is just simple solid