Fused Deposition Modeling (FDM) is an additive manufacturing (AM) process that has been commercialized by Stratasys. Besides Stratasys there are other machine suppliers today. In contrast to machines from Stratasys, the process parameters of these machines are accessible to allow the processing of materials from any material manufacturer. As with all AM processes, FDM requires the feedstock to fulfill certain demands. For this reason, the material should be specially selected or developed for the FDM process. However, the required material properties for good processability are currently not sufficiently known. Rather, no procedure is known for evaluating the processability of a material in FDM. This publication therefore presents procedures to evaluate the processability of thermoplastic polymers in FDM. For this purpose, weld seam quality and component distortion are identified and considered as important criteria. Taking relevant influencing factors into account, test specimens and methods are developed to define characteristic values such as the welding factor or the thin-walled bulging of components. This allows the comparison of different materials independent of the machine or data processing. The presented procedure is demonstrated by experimental investigations using PA 6. For this purpose, various material modifications based on PA 6 are created and the processability of every material modification is evaluated and rated using the presented procedure.