The only 1.5 x 1.5 flips I have seen are vinyl, and may cause issues with coins and long term storage.
There are 1.5 x 1.5 cardboard holders: http://www.wizardcoinsupply.com/pro...-coin-flips/
There are 1.5 x 1.5 cardboard holders: http://www.wizardcoinsupply.com/pro...-coin-flips/





















