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.
Use 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.