If you work in the Bangladesh RMG sector, you have heard the term 4-point inspection system hundreds of times. It appears in every buyer quality manual, every fabric purchase order, and every factory audit checklist. But there is a gap between knowing the name and understanding how the system actually works and why your factory needs the right machine to run it properly.
This guide explains exactly how the 4-point inspection system is applied in Bangladesh fabric mills and garment factories, how to calculate AQL 2.5, what common mistakes factories make, and what type of fabric inspection machine you need to run the system accurately at volume.
The 4-point system is a method for grading fabric rolls based on defect severity. It was developed by the American Society for Quality and has become the global standard for fabric inspection in the garment industry. In Bangladesh, every major buyer programme requires the 4-point system before fabric is dispatched from a mill to a cutting department.
The logic is simple. Not all fabric defects are equal. A small yarn snag that covers 2 inches is not as serious as a hole or a running weft bar that crosses the full width of the fabric. The 4-point system assigns penalty points based on defect size so that more serious defects carry heavier penalties. A roll that accumulates too many points is rejected. A roll that stays under the limit is accepted.
This is the grading table that every Bangladesh fabric inspector needs to know:
Defect Size | Penalty Points | Typical Examples |
Up to 3 inches (7.5 cm) | 1 point | Small stain, short yarn pull, minor broken thread |
Over 3 inches up to 6 inches | 2 points | Medium weaving defect, moderate shade bar |
Over 6 inches up to 9 inches | 3 points | Large weaving fault, wide stain, yarn contamination |
Over 9 inches or any hole | 4 points | Full-width barre, hole, running defect, large slub |
One important rule: no single defect can ever receive more than 4 points, regardless of how large it is. A running weft bar that spans the full length of the roll still only receives 4 points. However, if that same defect appears at multiple places across the width of the fabric, each occurrence is counted as a separate defect and scored separately.
The 4-point system does not work on raw total penalty points because rolls come in different lengths and widths. A short narrow roll and a long wide roll cannot be compared on the same raw score. The system normalises the score to points per 100 square yards so every roll is measured on the same basis regardless of its dimensions.
The formula is: divide the total penalty points by the inspected square yardage, then multiply by 100.
To calculate inspected square yardage: multiply the inspected length in yards by the fabric width in inches, then divide by 36.
Example: A roll is 120 yards long and 60 inches wide. Square yardage is 120 multiplied by 60 divided by 36, which equals 200 square yards. If the roll has 42 total penalty points, the score is 42 divided by 200 multiplied by 100, which equals 21 points per 100 square yards. This roll is accepted under AQL 2.5.
AQL stands for Acceptable Quality Limit. In Bangladesh, the standard used by almost all export-oriented garment factories and their fabric suppliers is AQL 2.5, which means a roll is accepted if it scores 28 points or fewer per 100 square yards.
Any roll that scores above 28 points per 100 square yards is rejected and either returned to the mill, renegotiated on price, or quarantined for further review. Some premium buyers working with high-end brands in Bangladesh apply stricter limits such as AQL 1.5 or AQL 1.0, which means a lower acceptance threshold. Always check your specific buyer specification because applying a looser standard than what the buyer requires will lead to quality claims later.
The 28-point threshold under AQL 2.5 is the Bangladesh RMG industry default and is what factories registered under BGMEA and BKMEA work to as a baseline.
The standard guidance in the Bangladesh RMG sector is to inspect a minimum of 10 percent of rolls in a lot. However, many fabric mills in Dhaka, Gazipur and Narayanganj now run 100 percent inspection for export orders because the cost of a quality claim from a buyer is much higher than the cost of inspecting every roll before dispatch.
If you are supplying to a factory that itself runs 100 percent incoming inspection, your rejected rolls come back to you. Inspecting all rolls before dispatch eliminates that risk. The economics of 100 percent inspection became much more viable once factories invested in a proper fabric inspection machine because machine-assisted inspection is faster and more consistent than manual inspection.
You can technically run a 4-point inspection manually. An inspector holds the fabric up to light, calls out defects, and another person records points. But at any volume above a few hundred metres a day, this becomes unreliable and slow for several reasons.
The inspection speed varies because different inspectors work at different speeds and tire at different rates. When an inspector is fatigued, they miss defects. A machine runs at consistent speed throughout every roll.
The yardage count is inaccurate when done manually. Yardage errors directly affect the penalty points per 100 square yards calculation and can lead to accepting a roll that should have been rejected, or rejecting a roll that should have passed.
Manual records are not verifiable. Buyers increasingly require digital inspection records for audit purposes. A piece of paper saying a roll passed inspection is not the same as a machine-generated roll report with timestamp, defect count and points per 100 square yards.
A fabric inspection machine solves all of these problems. It runs fabric at consistent speed over a backlit panel, counts yardage digitally, lets the inspector record defect points with a push-button counter, and prints or saves the roll report automatically.
Woven fabric mills in Bangladesh need a woven fabric inspection machine. Knit fabric mills need an open width or tubular knit inspection machine depending on whether your fabric is slit or inspected in tube form. Denim mills need a denim-specific machine with reinforced frame and cleaning system.
Never run knit fabric on a woven inspection machine. The tension systems are built differently and running knit on woven tension distorts the fabric and gives wrong yardage readings. The inspection results will be inaccurate and you will not catch the defects that buyers find when the fabric reaches the garment factory.
Yash Textile Machines makes separate models for all fabric types. Our machines are used by fabric mills supplying BGMEA and BKMEA factories in Dhaka, Gazipur, Chittagong and Narayanganj. Contact us at sales@yashtex.com or visit our Bangladesh page at www.yashtex.com/fabric-inspection-machine-bangladesh/ to get a quotation for your factory.
Running too fast is the most common mistake. Inspection speed should be between 10 and 20 metres per minute for most fabrics. Anything faster and small defects are missed.
Not separating each defect occurrence. If a weft bar runs the full width at 10 different places along a roll, that is 10 separate defects at 4 points each, not one defect scored once. Many inexperienced inspectors score a running defect once and underreport the penalty significantly.
Counting raw points instead of points per 100 square yards. A roll with 30 raw points on 500 square yards passes. The same 30 raw points on 80 square yards fails. You must normalise to square yards.
Inspecting only a sample when 100 percent inspection is required. Always check the buyer specification. Some buyers require 100 percent inspection and will reject a shipment if the inspection certificate covers only 10 percent.
