4-point fabric inspection system: formula, rules, limits

The 4-point fabric inspection system is a method for grading fabric rolls in which each visible defect earns 1 to 4 penalty points by its length, and the total is normalised to 100 square yards. It is the grading method almost every export buyer specifies for woven and knitted fabric. It is simple on paper and easy to get wrong on a noisy floor, which is why most rejections trace back to arithmetic, not to the fabric. This guide covers the rules as written in ASTM D5430 and as applied in buyer manuals used in Tirupur, Surat and Ludhiana.

1. What the system does

Each visible defect earns penalty points according to its length. Points are totalled for the roll and then normalised to a fixed area, 100 square yards, so that a 60-yard roll and a 150-yard roll can be judged against the same limit. The result is compared with the buyer's acceptance level, typically 40 points per 100 sq yd for a roll, and a tighter figure for the lot average.

2. Points by defect length

Measure the longer dimension of the defect. A 5-inch slub is 2 points whether it runs along or across the fabric.

3. The rules people forget

• Holes. Most buyer manuals score a hole or opening of 1 inch or less at 2 points and anything larger at 4 points, regardless of length. Many buyers simply score every hole as 4. Use the buyer's rule, not the generic one.
• Maximum 4 points per linear yard. However many defects fall within one yard, that yard contributes at most 4 points. Two 3-point slubs in the same yard count as 4, not 6.
• Running defects. Needle lines, barre, creases and similar continuous faults score 4 points for every yard they run. Many buyers reject the roll outright if a running defect exceeds a set length; one common manual says more than 4 continuous yards is an automatic reject.
• Only major defects are pointed. Minor faults that would not be visible in the garment are noted on the report but not scored.
• Not everything is points. Width, length shortage, shade (within the roll, roll to roll and against the approved swatch), skew or bow, GSM, shrinkage and odour are recorded separately with their own tolerances.

4. The formula

Points per 100 sq yd = total points × 3600 ÷ (length in yards × width in inches)

The 3600 is 36 inches per yard × 100 yards. It converts the roll's area into square yards and scales to 100 of them. For metric buyers the equivalent is points per 100 sq m = total points × 10,000 ÷ (length in metres × width in cm). Multiply a per-100-sq-yd figure by 1.196 to get per 100 sq m.

Worked example

A navy single-jersey roll, 120 yards long and 58 inches wide, has seven defects totalling 18 points after the per-yard cap.

18 × 3600 ÷ (120 × 58) = 64,800 ÷ 6,960 = 9.3 points per 100 sq yd.

Against a 40-point buyer the roll passes comfortably; against a strict 20-point kidswear buyer it still passes. A second roll with 24 points at 120 yd × 46 in gives 24 × 3600 ÷ 5,520 = 15.65, also first quality for most buyers. Try your own numbers on the 4-point calculator.

5. Typical acceptance limits

Many mills grade rolls as First quality (at or under the limit) and Second quality (over it) rather than pass and fail; the second-quality rolls go to the domestic market or back to the mill with a claim.

6. Sampling and procedure

• Inspect at least 10 % of rolls per colour, width and construction in a lot; 100 % if the previous lot from that mill failed or the buyer asks.
• Inspect on a frame at a steady speed, 15 to 20 yards per minute, under daylight-equivalent lighting, face side up.
• Record the yard position of every defect so the cutter can avoid it later. A roll map is the easiest way to show this.
• Check width at the start, middle and end; check shade at the start and end against the approved swatch and against the previous roll.
• Sign the report with inspector name, date and the standard applied.

7. 4-point versus 10-point

The older 10-point system scores warp and weft defects separately with up to 10 points each and compares total points with total yards, which penalises narrow fabric. The 4-point system normalises to area, has fewer categories and is what nearly all export buyers now specify, so it is the one to teach new inspectors.

8. Five mistakes that fail good fabric

Most disputed 4-point results come from arithmetic and procedure, not from the fabric. These five come up again and again in Indian export units:

1. Forgetting the per-yard cap. Two 3-point slubs in the same yard are logged as 6 points instead of 4, inflating the total. On a busy roll this alone can push a first-quality roll over the limit.
2. Using the wrong width. Ticketed width is used instead of the measured cuttable width, or, for tubular knits, the tube width is used when the buyer expects the opened width. Agree which width counts and write it on the report.
3. Mixing units. A roll measured in metres is run through the yards formula, or a per-100-sq-m limit is applied to a per-100-sq-yd result. A 40-point limit per 100 sq yd is about 48 points per 100 sq m.
4. Scoring holes by length. Most buyer manuals score holes by size (2 or 4 points), not by length. Check the buyer's hole rule before the first roll.
5. No yard positions. Without positions there is no roll map, the cutter cannot avoid defects, and any claim to the mill is weak.

Knitted fabric adds its own traps, such as rolls sold by weight rather than length. Our step-by-step guide on how to inspect knitted fabric with the 4-point system covers them, including how to convert a roll's kilograms into yards.

Doing it on the floor

On paper the inspector writes defect, length and yard, the office adds the points, applies the cap and runs the formula in Excel a day later. Fabric Inspection Software does the scoring, cap, formula and buyer comparison at the frame as each defect is tapped or spoken, and prints the roll map on the report. See how the fabric inspection app works, what a buyer-ready report looks like, or the plans and pricing, from ₹4,999 a month.

Questions people ask

Is the 4-point system only for woven fabric?

No. The 4-point system is used for knitted fabric as well. Knit buyers use their own defect lists (holes, needle lines, lycra out, barre) and often tighter limits of 20 to 28 points per 100 sq yd. Fabric Inspection Software stores each buyer's defect list and limit separately.

Does a 40-point limit mean 40 defects?

No. A 40-point limit means 40 penalty points per 100 square yards after normalising for roll size. A 120 yd × 58 in roll (193 sq yd) could carry up to 77 total points and still be under 40 per 100 sq yd, because the limit scales with area.

Which edition of ASTM D5430 applies?

The current edition is ASTM D5430-13, reapproved in 2017. Older buyer manuals cite D5430-07(2011); the point rules are the same in both, so a report following either edition is graded identically. Quote the edition your buyer's manual names on the report header.

How do I convert a 4-point score from square yards to square metres?

Multiply points per 100 sq yd by 1.196 to get points per 100 sq m, because 100 sq m is about 119.6 sq yd. A roll at 9.3 points per 100 sq yd is 11.1 per 100 sq m. Fabric Inspection Software reports in the unit set in each buyer standard (sq yd or sq m), and the free 4-point calculator shows both figures.