We proudly present Herbalist's Notebook of Cosmetics, marking 10th of the series. In the previous books, we tried to collect information and research results of the potential benefits on skin, only from the public space -literatures and articles. We did not include our own research to provide generally useful and citable information. However, as we have been working in the industry for almost 20 years, more customers are asking about our own way and effort to develop innovative product with raw materials known for so long time. This book is an answer to those questions, and we curated 15 representative plants with proven efficacies that all the cosmetics researchers and brands are looking for. In addition, each chapter has comprehensive explanation, how we are evaluating skincare efficacies, as well as the references useful for the readers.