The paper industry needs to implement several concurrent strategies. In particular, the industry can be expected to view recycling as a central part of its activities. These activities will be focused on the intense demand of chemical and biochemical strategies to enhance bonding within paper and paperboard. Nowadays, on average, 55% of fibrous compositions for papermaking are made of recycled fibers. In this field, about 65-70% are fibrous compositions intended to be used for packaging papermaking. Corrugated cardboard is one of the most significant examples, since it is made of fluting (internal part) and test liner (external part). In test liner mills, fibrous compositions are made of 50% paper cuts from the cardboard industry and the rest of other types of paper and cardboard. Some test liner papers have low content of mineral fillers. While recycling, fibers get damaged due to the hornification phenomena and mechanical refining of the pulp (with the purpose of enhancing the mechanical properties). The producer does not have many alternatives to address this situation: to increase the quality of the pulp, to slightly refine the pulp or to add some chemical additives that enhance mechanical properties. One strategy or alternative to this situation could be biorefining processes of the pulp. The present work aims to biorefine a pulp made of recycled fibers with the purpose of restoring the mechanical properties of the industrial test liner or improving them and making possible the addition of mineral fillers in order to decrease the production costs. It was observed that, at best, the tensile strength improved by 55% with regard to the original breaking length of the industrial test liner