Definition
A temporary backing that protects the adhesive before installation. It is peeled away during fitting and does not remain as a protective layer on the vehicle.
Why it matters
Distinguish liner thickness from installed film thickness when reading specifications. Some products also have a temporary cap sheet on the exposed side; neither shipping layer should be confused with the permanent top coat.
Apply the concept
Choosing an installer and understanding the work
Practical questions about preparation, cutting, edges and handover, plus realistic limits for DIY kits.