Oki PT390 Manuel D'utilisation page 43

- Cleaning the Lower cutter
Using a general-purpose utility knife, flathead screwdriver, or similar tool,
remove the adhesive matter adhering to the surface and edge of the Lower
cutter.
Note: Be very careful not to damage the edge of the Lower cutter when handling
the utility knife or screwdriver. Also take care not to dent or otherwise
damage the platen roller. A dent on the platen roller may result in
incomplete printing or line feed errors.
Lower
cutter
41