Legal analysis: it can be determined. 1, generally about 3-5 samples, as long as the characteristics are fully reflected, they can be used as sample comparison materials.

2. Apply for handwriting identification to the criminal identification center of the public security organ at or above the municipal level, and engage in handwriting judicial identification.

3. Generally, the client is required to provide original materials. In some cases, if it is difficult to obtain the original materials, the appraisal institution may send someone to the scene to take photos or provide a copy with the signature and seal of the source.

Legal basis: Article 63 of the Civil Procedure Law of People's Republic of China (PRC) includes:

(a) Statements of the parties;

(2) Documentary evidence;

(3) Physical evidence;

(4) Audio-visual materials;

(5) Electronic data;

(6) Testimony of witnesses;

(7) Appraisal opinions;

(8) Records of the inquest. Evidence must be verified before it can be used as a basis for ascertaining facts.