1. A process for manufacturing a structured material comprising the steps of:(a) providing cellulose fibres;
(b) providing at least one filler comprising calcium carbonate;
(c) combining the cellulose fibres of step a) and the at least one filler of step b) at a weight ratio of fibres to filler on a dry weight basis of from 1:33 to 10:1;
(d) fibrillating the cellulose fibres in an aqueous environment in the presence of the at least one filler from step c) until a nano-fibrillar cellulose gel is formed; wherein the formation of the gel is verified by monitoring the viscosity of the mixture in dependence of the shearing rate, wherein the viscosity decrease of the mixture upon step-wise increase of the shearing rate is larger than the corresponding viscosity increase upon subsequent step-wise reduction of the shearing rate over at least part of the shear rate range as shearing approaches zero;
(e) providing additional non-fibrillated fibres in the form of a fibre web; wherein before, during or after the addition of further non-fibrillated fibres in the form of a fibre web in step e), but after step d) and before step f), at least one further filler is added, wherein the at least one further filler and/or pigment comprises at least a fraction of particles having a median diameter d50 in the nanometer range;
(f) combining the nano-fibrillar gel of step d) with the non-fibrillated fibres in the form of a fibre web of step e), so that the combination of the nano-fibrillar cellulose gel and the non-fibrillated fibres in the form of a fibre web includes 0.5 to 20 wt. % of the nano-fibrillar cellulose gel, expressed by the cellulosic content of the nano-fibrillar cellulose gel, on a dry/dry basis; and
(g) manufacturing a structured material from the combination of the nano-fibrillar cellulose gel and non-fibrillated fibres in the form of a fibre web.