Are you making a leather wallet, business card holder, or other item to use with bank, business, or loyalty cards? You want to ensure the customer gets a wallet that fits their cards easily, but you don't want to empty your own wallet each time you make a new item to slightly stretch out the leather.
 
A great solution is to get a set of acrylic business card blanks. These are roughly the thickness of three credit cards, so adding them to pre-stretch and form your slots is easy.
 
We use them by placing one in each slot for about 15 minutes. This slowly works the card into the slot space to release any excess glue or tight areas, like the corners. During this time, we condition the leather and then remove the card afterward. Your item is then ready to go.
 
You'll find that having just this short time in the slots really helps to ease cards in and out of the brand new item.