Classification of indicators of poor quality display of the plantar surface of bare feet of living persons

12 indicators of poor quality of papillary prints of the plantar surface of bare feet were revealed during traditional fingerprinting of living persons. Indicators are classified and arranged in chronological order as the total quantitative indicator decreases when studying 700 special fingerprint cards over two periods of time. It was concluded that the bulk of the indicators of poor quality of the plantar surface prints is associated with such indicators as prints from wet and dirty soles of the feet, repainted and smeared prints. A specific indicator only for the sole of the feet - “smeared print of the upper part of the big toe” was identified. These indicators are divided according to three more indicators for poor quality of footprints. It has been established that the quality of footprints depends on the quality of the technique and technology used to obtain them and the appropriate control by a competent person. This makes it possible to optimize measures to improve the quality of a special fingerprint card for displaying papillary prints of the plantar surface of the bare feet of living persons for comparative studies, especially when it is impossible to identify a person by the fingers and palms of the hands, as well as in connection with the use of biometric plantar terminals in the near future. Theoretical and practical recommendations for taking prints of the papillary sole of the feet are given in the development of the author’s previous works. This will affect the encoding of the image in the automatic fingerprint information system and its search characteristics, and most importantly, the final result for the prompt and objective identification of the person.