1. Examination of pre-press production quality, providing parameters for pre-press.  By examining the proofing know graphic layout specifications, graphic content, positioning alignment is correct, page colors, levels of inspection, gray balance and so on whether met quality requirements; while providing color for pre-press operations, gray balance, dot value and other parameters. 

2.To provide proof. Customer proofs predicting quality standards in print quality results confirm the official printed and signed acceptance.  Customer signature of proof as between producers and customers to the agreement reached that the print quality. 

3. Provide criteria for printing proofs. Printing to the proofing standard for print production and testing of print quality.