Continuous Filament Fabrication (CFF) is similar to FFF in many ways but has the added function of incorporating a continuous filament of fibre into the previously laid down extrusion of base material. The continuous fibre can be incorporated throughout the printed part or applied to localised areas (by whole layers) where additional strength is required.

Unique to this process is the Markforged machine which uses proprietary *Onyx or Nylon material as the primary substrate with a continuous fibre of carbon, Kevlar or glass fibre. Material properties similar to that of 6061 aluminium are achieved when Onxy and continuous carbon are combined.

*Onyx – Micro-carbon reinforced Nylon