CUSHIONAIRE Women's Luna Cork Footbed Sandal + Comfort

Q: What’s the difference between the black, black nappa, and the black oily colors - anyone know?

Just the appearance. The black oily has a wax greasy hine to it. Nappa is a soft material with flat black look

Q: Should I size up a full size or a half size for these sandals?

I believe the length is true to size but with wider feet or heels or high arches i would advise getting 1 to 2 sizes larger. Im a true 9.5 but always buy size 10 because of extra high arches ( the top always digs into my arch). I ordered 10 wide in these and length and adjusted arch height is good (just right with no extra room at all) but the heel sides are digging in a bit (kinda narrow). Im thinking that 11 wide should fit better overall