Abstract: The invention relates to a method of determining toolpaths for an infill structure for a digital 3D model. The invention provides for a framework for planning toolpaths with control over the adaptive width for minimizing over- and underfill and introduce a beading scheme which reduces the bead width variation compared to the state of the art. We show that this framework supports various control schemes (so-called ‘beading schemes’) for determining the bead spacing and extrusion widths. Furthermore we present an approach to accurately realize adaptive bead width. The proposed method provides for a geometric framework allowing various adaptive bead width control schemes used to generate contour-parallel toolpaths which minimize under- and overfill.