To attach your Backbone to your phone, first clean the surface with a clean cloth to remove dust and grease.
Then differentiate between applying with or without nanofoil:
Do not use nanofoil:
Do not use the nanofoil on rough surfaces such as silicone or leather. Here you stick your Backbone directly onto the surface, you don't need the nanofoil.
On particularly smooth surfaces, such as glass or marble, we recommend that you use the nanofoil. First apply the nanofoil to the surface and then stick your Backbone onto the nanofoil.