We strongly encourage you not to skin the back of your Sandstone Black OnePlus One. While covering it with a skin will definitely make it look cool, it won't improve the fantastic grip already offered by the Sandstone finish.
With that being said, adding a front and matching camera skin would be a great idea. Every front skin comes packaged with two anti-glare screen protectors, providing full protection for the front of your device.
At dbrand, we care about user experience. In the end, the choice is entirely yours."