Hand lay-up fabrication has been used for forming composite structures since ancient times as it can be performed as long as the mold, skills, and materials are available. On the other hand, the hand lay-up fabrication work itself relies on human skills, which means that the finish differs according to the operator carrying out the work, the quality of the product differs among parts depending on the ease of forming, and that defects such as bubbles tend to occur easily. In this study, the experiment quantified techniques that are not visibly apparent and considered to be tacit knowledge.