Four Point System

Quality control department is responsible for producing a good quality product. How do they achieve it?..
Quality assurance or quality control department will perform the necessary inspection of the fabric to make sure it is matching the specification and they also make sure it is defect free [slubs, hole, missing yarn, conspicuous yarn variation,end out, soiled yarn, wrong yarn, dye spot, color shade/smudge, needle line, etc.]. They perform frequent random inspection of the fabric to determine the efficiency of the department which helps to identify and correct the problem. This reduces the waste produced in the department and also helps to produce a good quality product. 

Manufacturer should certify their product as per the specification provided by the customer. Manufacturer and customer should mutually agree to that grading system to prevent confusion or conflict. It helps to prevent return of the goods due to disagreement in terms of number of defects and its particulars (length, width, front/back...). So a 
standard grading system is used to identify the defect and grade it. A grading system has been developed by American Society for Quality Control (ASQC) and is called Four point grading system. 

Four point system is a fabric grading system developed to assign points to the defects based on its size and type. In this grading system, points will be assigned to the fabric based on number of defects and its lengths. The details of grading as follows;

Size of defect                           Number of penalty points

3" or less                                   1
Over 3" to 6"                               2 
Over 6" to 9"                               3
Over 9"                                       4

Fabric will be graded and points will be assigned as per the above guidelines. Then the fabric will be classified as first class or second class fabric using the below guidelines.

Penalty points per 100 sq/yd

50" or less in width                             More than 50" in width                          Class

Less than 41 points                              Less than 45 points                                  First
More than 40 points                              More than 44 points                                 Second             

General guidelines:
  • Fabric should not have more than 1" bow or 0.5" bias for 60" width and this tolerance shall not exceed 2% bow and 2.5% bias on other widths.
  • No yard shall be assigned more than 4 points.
  • Defect should be counted only on face side.
For more information regarding the grading system, please refer to ASTM D5430.

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