With a cleaving knife fibres can be cut easily and effectively.
The diamond blade inside the fibre "cleaving knife" is at least fifty times sharper than the best razor blade.
The same technology used in stationary cleaving tools now comes in pen size. With this cleaving knife fibres can be cut easily and effectively. The fibre breaks cleanly and reliably at the position scratched by the diamond. All it takes is an axial pull. A subsequent treatment of the clean break is very easily done and can even be omitted.
The diamond blade can be hidden in the tip of the tool to prevent you from cutting apart those important documents you just wanted to sign.