The contents of signature handwriting identification include: when making an identification request, the submitting unit shall be required to provide a comparison sample. If the inspection unit cannot provide samples, only a few appraisal institutions can identify the finished documents within three months after repeated tests; The appraisal institutions of public security departments can rarely appraise the documents made within half a year, and the detection rate of inspection and appraisal is not high. The cost varies from province to province, so it is necessary to find a special institution for handwriting identification, and the cost is generally between 800-2000 yuan. Handwriting identification is a special technology to identify the writer according to the characteristics of people's writing skills and habits, as well as the reflection in writing handwriting and painting. The main task is to prove whether the handwriting on the documentary evidence is the same person's handwriting and whether the handwriting on the documentary evidence is the suspect's handwriting through the same handwriting identification test. Handwriting identification can test not only normal handwriting, but also handwriting with changing writing conditions (including writing posture, writing tools, filling, etc.). ), deliberately camouflage handwriting (including left-handed handwriting, ruler-drawn handwriting), imitate handwriting, and draw handwriting. When the same person writes with the same pen, the characteristics of pen marks can also be used to enrich the basis for identifying the writer.