There are various reasons to post-process. Two reasons are given as follows: (1) the process is not good enough to make a part; therefore, post-processing is used to compensate for what the process cannot do. The post-processing ranges from intensive cleaning to treatments lasting for several hours or days. If an AM process is developed well, post-processing is not required. For example, if a polymer part made from stereolithography is not cured, post-curing as a post-processing is applied to fully cure it. Since the process (stereolithography) did not give well-cured parts, the post-processing is done to compensate for the demerit of the process, (2) process is not used for all purposes. Post-process is used when a part is required to have a property that is not provided by the process because the process is not meant to provide that, etc.