NOVELTY - A sacrificial feedstock (C1) for extrusion of ribbons containing sacrificial extrudate and high-aspect-ratio functional material, comprises an organic polymer, a solvent, and at least one optional additive, where the sacrificial feedstock has a yield strength of greater than 100 Pa or a viscosity of greater than 104 cP at a shear rate of less than 10 sec-1 to enable the ribbon to maintain structural integrity, and the sacrificial feedstock can be removed from the ribbon, leaving the functional material in place with an aspect ratio of greater than 0.3.    USE - For extrusion of ribbons; in the combination used in forming solar cell, fuel cell, and plasma display panel.    ADVANTAGE - The sacrificial feedstock has viscosity of 0.1-300 Pas when measured at 20 degrees C on a Brookfield viscometer at low, moderate and high shear rates; or yield strength of greater than 100 Pa, a viscosity of greater than 104 cP at a shear rate of less than 10 sec-1. The sacrificial material does not include a filler material that would not burn-out during a sintering process of the functional material at 600-800 degrees C for a time period of less than one minute. The sacrificial material satisfies burns out during firing or sintering of the functional material, such that the sacrificial material is substantially removed from the substrate.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for following:    (1) a material set, comprising sacrificial feedstock (C1) and a functional material that forms a ribbon with the sacrificial feedstock without the sacrificial feedstock and the functional material substantially intermixing;    (2) extruded ribbon of material, comprising a functional material having an aspect ratio of greater than or equal to 0.3, and an unfilled sacrificial material (C1) on at least one side of the functional material;    (3) a combination comprising a substrate, and an extruded ribbon of material on the substrate, where the extruded ribbon comprising is functional material having an aspect ratio of greater than or equal to 0.3, and an unfilled sacrificial material (C1) on at least one side of the functional material;    (4) forming (P1) conductive lines on a substrate, involving extruding a ribbon of a functional material having an aspect ratio of greater than or equal to 0.3 and a sacrificial material (C1) on at least one side of the functional material; and    (5) a solar cell structure, comprising a substrate; and at least one gridline formed on the substrate, where the at least one gridline has an aspect ratio of at least 0.3 and is formed by extruding onto the substrate a ribbon of a functional material having an aspect ratio of greater than or equal to 0.3 and a sacrificial material (C1) on at least one side of the functional material.