Originally, one of the most common methods of making graphene involved quickly ripping strips of adhesive tape off of solid blocks of graphite. This resulted in one-atom-thick sheets of linked carbon atoms – graphene, in other words – being stuck to the tape in flake form.
A more production-friendly approach involves depositing graphene on metal foil. In both cases, however, the graphene must be removed from the tape or the foil and transferred onto the substrate (such as silicon or glass) used in the particular electronic device or other application. That transfer process can be very fiddly, often resulting in the graphene being damaged or contaminated.