In our world-wide never ending attempt to find the perfect corner rounder for playing cards we recently came across this corner rounder and it’s the best one we have ever used. The corners are clean and the ergonomic handle allows you to comfortably punch hundreds of cards. 

The 3mm corners are the exact sizes as the standard Bicycle corners making this great for
Corner Rounder for card gaffing. 

3mm same radius as Bicycle Playing Cards

5mm perfect for shallow corner short

8mm for deep corner short