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ASTM standard

ASTM D5430 — the 4-Point System

The fabric inspection standard most apparel buyers write into their contracts, explained in full: how defects are scored, what conditions the standard requires, and where its limits lie.

What the standard is

ASTM D5430 — Standard Test Methods for Visually Inspecting and Grading Fabrics — defines the 4-Point System, the most widely used fabric inspection method in the garment industry. It converts subjective visual defects into a single comparable number: penalty points per 100 square yards.

Its value is normalisation. A 40-yard roll and a 400-yard roll cannot be compared on raw defect counts, but they can be compared on points per unit area. That is the whole idea.

Penalty points by defect length

Defect lengthMetric equivalentPoints
Up to 3 inchesUp to 7.5 cm1
Over 3 up to 6 inches7.5–15 cm2
Over 6 up to 9 inches15–23 cm3
Over 9 inchesOver 23 cm4

The measurement is the defect's longest dimension, whether that runs along the length or across the width. No single defect can exceed 4 points however long it is — a 30-inch running fault still scores 4.

The scoring formula

Points per 100 yd² = (Total penalty points × 3600) ÷ (length in yards × width in inches)

Use the 4-Point calculator →

Required inspection conditions

ConditionRequirement
Inspection speedNo greater than 15 yards per minute
IlluminationMinimum 80 foot-candles on the fabric face
Viewing distanceApproximately 3 feet
Surface scoredFace of the fabric only

Acceptance limits in practice

ASTM defines the scoring method, not the pass mark. The threshold comes from the buyer.

Points / 100 yd²Typical treatment
Up to 15Premium programmes, technical and performance fabric
Up to 20The most common apparel threshold
21–28Accepted by some buyers, often with a price adjustment
Above 28Generally rejected or downgraded to seconds

The limitation built into the method

Read the inspection conditions again. The standard requires fabric to move at no more than 15 yards per minute, under strong light, watched by a person three feet away. Those requirements exist because human visual inspection needs them.

Two consequences follow. First, inspection cannot run at production speed, so it happens after the fact on a sample — commonly 10% of rolls. Second, everything the sample misses reaches the customer. The 4-Point System is an excellent grading language and a poor detection mechanism, and it was never designed to be otherwise.

Common questions

What does ASTM D5430 cover?

ASTM D5430 is the standard test method for visually inspecting and grading fabrics. It defines the 4-Point System used across the apparel industry to convert visible defects into a comparable numeric score.

Is the 4-Point System mandatory?

No standard is mandatory in itself — it becomes binding when a buyer writes it into the purchase contract, which most apparel buyers do. The acceptance threshold is set by the buyer, not by ASTM.

Does it apply to knitted fabric?

Yes. The method covers both woven and knitted fabric. For knits the scored defects are typically holes, drop stitches, barré, lycra breaks, oil lines and needle lines.

What percentage of production should be inspected?

The standard does not mandate a sampling rate. Industry practice is commonly 10% of rolls, selected randomly. Full inspection is rare manually because of the speed limit the standard itself imposes.

What is the 4-points-per-linear-yard rule?

Most buyers apply a secondary cap: no single linear yard may carry more than 4 penalty points. This prevents a roll with one severe concentrated defect from passing on a favourable overall average.

Grading happens after the fabric exists. Detection does not have to.

The 4-Point System tells you how bad a roll turned out. Knit-I tells the machine to stop while the roll is still good — inspecting every course at production speed, on 100% of output rather than a 10% sample.

See Knit-I on your machines →
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