Well if you are looking for canvas pieces; (such as the ebene or Monogram) these will have the snap closure button with the leather cover. I've watched a review on YouTube by LoniGoLux where basically she says to close around the snap button.. not actually pushing down on it to prevent damage to the snap closure. (Pressing down on the sides of the canvas)
Other wallets such as the epi leather Victorine's.. do have the metal closures.
So it's really a preference, if you are set on a canvas piece they will have the leather colored closure. If not, you can always go for the epi or vernis victorine option.