How to Use the 4-Point System Fabric Inspection

Quality Control in Fabric manufacturing is critical, especially when dealing with knits, which are prone to various defects like holes, loose threads, and inconsistent textures. One of the most widely used methods for inspecting knit fabrics is the 4-Point System. 

This standardized system helps manufacturers and quality control teams evaluate fabric quality and determine its acceptability before moving on to production. In this blog, we’ll explain how to use the 4-Point System for knits fabric inspection.

What is the 4-Point System?

The 4-Point System is a standardized inspection method used globally in the textile industry to assess fabric quality. It assigns penalty points to fabric defects based on their size and severity. The total number of points is used to determine whether the fabric meets acceptable quality standards.

How the 4-Point System Works for Knits Fabric Inspection

The 4-Point System assigns 1, 2, 3, or 4 points to fabric defects, depending on their size and impact. The fewer the points, the better the quality. For knit fabrics, this method is especially useful in identifying defects that could affect the garment's appearance and durability.

1. Define the Inspection Area

Before starting, you must clearly define the area to be inspected. Typically, the inspection is done in full width (selvage to selvage) and 10-yard increments of fabric. Each section is checked for defects and points are assigned accordingly.

• Tip: Use a flat inspection table with adequate lighting to see the fabric clearly. A fabric inspection machine with a roller is also helpful for consistency.

2. Identify and Classify Defects

The next step is identifying and classifying defects that appear during the inspection. Common defects in knit fabrics include:

• Holes or tears
• Stains or oil spots
• Yarn defects (e.g., missing loops, snags, or broken yarns)
• Fabric distortion or uneven texture
• Color inconsistencies or dye streaks

Each defect type is recorded, and the size of the defect determines the points assigned.

3. Assign Points Based on Defect Size

According to the 4-Point System, defects are categorized and assigned points as follows:

• Holes and openings in the fabric, regardless of size, automatically receive 4 points.
• If there are multiple defects in the same section of fabric, each defect is scored separately and added up.

4. Calculate the Total Points per Roll

After inspecting the entire fabric roll, sum the points for all defects found. The total points should then be divided by the total yardage (or meterage) of the fabric roll to determine the points per yard or meter.

• Formula:
  
  
  Points per yard=Total Yards Total Points​ For example, if a roll of fabric is 100 yards and has accumulated 200 points, the points per yard would be:
  $$\frac{200}{100}=2\text{ points per yard}$$

5. Determine Fabric Acceptance Based on Points

The final step is to determine whether the fabric passes or fails based on the acceptable point threshold set by the buyer or manufacturer. Typically, fabric is considered acceptable if it averages 3 points or less per yard. However, this limit can vary depending on specific buyer requirements or product standards.

Common Defects in Knits Fabric and How to Score Them

Here are some examples of defects commonly found in knit fabrics and how they would be scored under the 4-Point System:

1. Small Hole (less than 3 inches): 4 points (holes always score 4 points).
2. Yarn Snag (4 inches): 2 points (based on length of the snag).
3. Dye Streak (10 inches): 4 points (since it exceeds 9 inches).
4. Loose Threads (5 inches): 2 points (depending on length of loose thread).

By consistently applying the 4-Point System, you can ensure that only high-quality fabric is approved for further production, minimizing defects in the final garments.

Tips for Effective 4-Point System Inspection

• Train Your Inspectors: Ensure that your quality control team is trained in identifying defects and applying the 4-Point System correctly.

• Use Proper Lighting: Good lighting is essential for spotting minor defects in the fabric.

• Set Clear Standards: Work closely with buyers to set acceptable thresholds for defect points, which can vary based on the end use of the fabric.

• Record Inspection Results: Always document the inspection process, including defect types, point totals, and any actions taken (e.g., rejection, rework).

Conclusion

The 4-Point System is a highly effective method for inspecting knit fabrics, ensuring that defects are identified and scored consistently. 

By following this system, manufacturers can improve fabric quality, reduce returns, and maintain strong relationships with buyers. 

Proper use of the 4-Point System also helps in maintaining consistency across large orders, ensuring that only the best fabric reaches the production floor.