Based on the Honshu Karambit.
The knife was masked to protect the handle. Then the knife sandblasted, to create better adhesion. The surface is cleaned using a metal prep cleaner which also helps the paint adhere. Then a self etching primer is applied to create a strong base coat. Then a stencil is used to create sections of different reflectivities, then a coat of clear red. Finally, a clear coat of Imron is applied. Imron is a durable clear coat used on NASCAR. The clear coat will resist most minor scratches, but scratching hard objects like rocks or metal can damage the paint.