GA/T 1580-2019Forensic sciences - Code of practice for examination of plate-based printing documents (English PDF)

2.1 Inspection of samples and samples

Inspection of materials and samples shall be in the following order.

a) Form of analysis material.

1) The inspection materials are not formed by plate making, communicate with the inspection unit or directly enter Chapter 3;

2) The inspection material is formed by plate-making printing. Continue to the next step.

b) To determine the inspection conditions of the inspection materials.

1) If the inspection materials do not meet the inspection requirements, proceed directly to Chapter 3;

2) If the inspection materials have the inspection conditions, continue to the next step.

c) Comparison conditions of analysis samples.

1) If the sample does not have the comparison conditions, it is required to supplement the sample or directly enter Chapter 3;

2) If the samples have comparison conditions, continue to the next step.

2.2 Comparative test

2.2.1 Recognition method of printing features

Features such as direct observation, microscopic observation, measurement, spectral inspection, and composition inspection can be used to find, select, and extract features.

2.2.2 Method of comparison test

The detailed feature comparison method, coincidence comparison method, connection comparison method, and measurement comparison method can be used for comparison.

2.2.3 Judgment of plate making method

Judging by Chapter 2, proceed to Chapter 3.

2.2.4 Judgment of co-printing

Can be based on the content of graphics and text; relative position; detail form; dot form; color density; ink defects; printing plate wear; revision;

Binding and other features are comprehensively judged.

2.2.5 Judgment of printing in the same batch

Can be based on the content of the layout of the text; layout specifications; relative position of the text; the shape of the dots; the shape of the details; ink composition and other characteristics Comprehensive judgment.

GA/T ××××-××××

3.1 Making feature comparison table

3.1.1 Make a feature comparison table of selected inspection materials and sample plate-making printing features. Feature selection must be comprehensive, with particular attention to selecting detailed features.

Sign.

3.1.2 The comparison table can be produced by copying and cutting, computer scanning, and photographing.

3.1.3 The valuable features in the comparison table shall be identified one by one; generally, the same features are marked with the same color, and the different features are marked with different colors.

3.2 Formation of inspection records

3.2.1 The contents of inspection records shall include (but not limited to) the case number, inspection process, inspection opinions, inspection time, and use of instruments Name, inspector, etc.

3.2.2 The appraiser shall write or print the inspection record and sign it for confirmation.

3.2.3 When the opinions of the appraiser are different, the inspection opinion and the discussion time of the appraiser should be indicated in the inspection record and signed for confirmation.