An FFF system (FusedForm FF600) was used to 3D print our topological insulator samples from polylactic acid (Matterhackers "Natural PLA PRO", 1.75 mm diameter) using a 0.8 mm nozzle and a layer height of 0.2 mm. Care was taken to ensure that all the acquired spools of filament came from the same lot to avoid variations in material properties from sample to sample. All samples were printed on 1/16-inch-thick aluminum substrates, which do not influence the transmission through the sample. Green painter's tape (3M Scotch 401+ Masking Tape) was applied to the aluminum sheet prior to printing to improve adhesion of the PLA to the substrate. Toolpath generation was performed using the Simplify3D slicing engine (v4.1.2). The slicing parameters (Table ) were selected iteratively to maximize the refractive index of the printed part while maintaining fidelity of the geometric features and constraining print times to ~33 hours. Shorter print times can in principle be achieved by using custom high-index thermoplastic materials and decreasing the infill percentage. Common defects that arise due to the printing process included polymer drool between adjacent structures, unwanted z-height deposition that resulted in inconsistent height of the structure, voids in the areas where contiguous circular beads meet, as well as warpage. These issues were mitigated through manipulation of the slicing engine parameters, resulting in the structures used in this work.