What are fabric defects?
Fabric defects are visible flaws in a length of cloth: holes, slubs, broken or missing yarns, stains, shade variation, creases, and weaving or knitting faults. They arise at the mill, from yarn quality, loom or machine settings, dyeing, printing, or finishing, and from handling.
Catching them at the fabric stage matters because this is the last point before cutting. A defect found on the roll costs a metre of fabric; the same defect discovered after a garment is sewn costs the whole garment, plus the labour in it. Fabric inspection is the gate that keeps flawed cloth off the cutting table.
So fabric defects are not judged one by one as pass or fail. They are counted, scored by severity, and totalled, so a whole roll can be graded on a single number and held to an agreed limit.
How the 4-point system scores a defect
The 4-point system assigns each defect 1 to 4 penalty points by its length. It is the method most of the industry uses, standardised in the United States as ASTM D5430, Standard Test Methods for Visually Inspecting and Grading Fabrics.
- The point scale by length: a defect up to 3 inches scores 1 point; over 3 up to 6 inches scores 2; over 6 up to 9 inches scores 3; and anything over 9 inches scores 4. The same scale applies whether the defect runs along the length or across the width.
- A cap of 4 points per yard: no single linear yard of fabric can be penalised more than 4 points, however many defects it holds. A single defect also never scores more than 4.
- Holes and full-width faults: any hole larger than a pinhole is treated as a major defect and scored 4 points. A full-width defect or a splice also takes the maximum.
- The selvage rule: defects within one inch of either edge are usually disregarded, because that band is trimmed off in cutting. The standard scores what will actually be used.
- Continuous and running defects: a defect that runs for more than nine inches, or continues down the roll, is scored 4 points for each linear yard it affects, so a persistent fault is penalised far more heavily than a one-off flaw. That is deliberate, because a running defect usually signals a machine problem, not bad luck.
The standard is a grading method, not a quality level in itself. It does not say a fabric is good or bad; it gives buyer and supplier a shared, numerical way to describe how many defects a roll carries, so an acceptance limit can be agreed rather than argued. It also normalises the count so wide and narrow rolls are judged on the same footing, which the next step handles.
How to calculate defect points per 100 square yards
A raw point total means nothing until it is normalised for the size of the roll. The 4-point system converts it to points per 100 square yards, so a 44-inch roll and a 60-inch roll can be compared on the same scale.
The formula is: points per 100 square yards equals total defect points times 3,600, divided by the fabric width in inches times the roll length in yards. The 3,600 is 100 times 36, converting yards and inches into square yards.
Take a 60-inch-wide roll, 100 yards long, that scores 9 defect points. That is 9 times 3,600, divided by 60 times 100, which is 32,400 divided by 6,000, or 5.4 points per 100 square yards. Against a 40-point limit, the roll passes as first quality with room to spare.
Because the result is a rate, not a raw count, it holds across roll sizes and lets a buyer set one acceptance number that applies to every fabric and every lot.
What counts as an acceptable defect level?
There is no universal pass mark. The acceptance limit is set by the buyer and written into the contract, but the industry works around well-known defaults.
- The common ceiling: 40 points per 100 square yards is the most widely used limit for standard apparel fabric. A roll below it is graded first quality; above it, second quality, to be re-priced, re-cut, or rejected.
- Tighter for premium: high-end and outerwear programmes often demand fewer than 20 points per 100 square yards, while basic or value-tier fabric may be allowed 40 to 60. The number should match the product.
- Roll versus shipment: many standards set two limits, a higher one for any single roll and a lower average across the shipment, so one poor roll cannot be hidden inside a good batch.
The grade is not academic; it drives money. A roll that falls to second quality is typically repriced, sent back, or released only for less demanding cuts, and a shipment that misses the average limit gives the buyer grounds to reject or renegotiate. Setting the number too loose ships flaws into production; setting it too tight rejects usable fabric and pushes up cost. The right ceiling is the one that matches how visible a flaw will be in the finished product.
ASTM D5430 offers more than one point-assignment option, and the score for the same roll can differ between them. The practical rule is to name one option in the contract and have both sides inspect the same way, so a disagreement is about the fabric, not the method.
Common fabric defects and what causes them
Most defects trace back to one of four stages. Knowing the cause is how a buyer turns an inspection report into a corrective conversation with the mill.
- Weaving and knitting: broken or missing picks and ends, floats, slubs, thick and thin places, holes, and reed marks, from yarn faults or loom and machine settings.
- Dyeing and printing: shade variation across or along the roll, streaks, barre, dye stains, and misprints or off-register prints.
- Finishing: skew and bow (the weft running off-square), creases set in by heat, and uneven or pilled surfaces from over-processing.
- Handling and storage: oil and grease stains from machinery, contamination and colour fly, and abrasion or crush marks from rough handling, transport, or damp storage of the rolls.
Some of these overlap with the fabric tests a buyer already runs, such as colourfastness for shade and staining or abrasion resistance for surface wear. Inspection catches the visible flaw; the lab test catches the performance failure behind it.
Fabric inspection versus AQL: grading a roll is not sampling a garment
This is the distinction that trips buyers up, and getting it right is what makes a quality programme coherent. The 4-point system and AQL are both quality gates, but they measure different things at different stages.
- The 4-point system grades fabric: it scores defects across a roll of cloth, by area, before anything is cut. The output is a points-per-100-square-yard grade for the material.
- AQL samples finished units: AQL, the acceptable quality limit, is a statistical sampling plan applied to finished garments in a production lot. It pulls a sample, counts defective units, and accepts or rejects the lot against a set limit.
So a lot can pass AQL on workmanship yet still be cut from poorly graded fabric, and clean fabric can still be sewn into a lot that fails on stitching. A buyer needs both: the fabric graded on the roll, and the finished garments sampled in the box.
The 10-point and other systems
The 4-point system is dominant, but it is not the only one. A few older or niche methods still appear in contracts, which is why it is worth naming the system you mean.
- The 10-point system: an older method that scores warp defects up to 10 points by length and weft defects by the fraction of the width affected. It is more complex and now far less common than the 4-point.
- Other schemes: the Graniteville 78 and Dallas systems also exist, and some mills use in-house grids. The safest practice is to specify ASTM D5430, the 4-point option, so there is no ambiguity about how a roll was graded.
How to spec fabric inspection in sourcing
On a fabric contract or a supplier quality manual, fabric inspection is a short, firm clause when it names the system, the sample, the limit, and the evidence.
- Name the system and option: state ASTM D5430, the 4-point system, and the specific point-assignment option, so buyer and mill grade the same way.
- Set the sample and the limit: how many rolls are inspected, commonly at least 10 percent, and the acceptance ceiling in points per 100 square yards, with a tighter number for premium fabric.
- Require the report and tie it in: ask for a fabric inspection report per lot showing points and defect types, and fold it into the wider sourcing and quality programme rather than treating it as a one-off check.
Knowing which inspection standard, limit and test fit a given fabric, market and product is the fashion-native detail Apshan's Nari knowledge graph answers, cited to source, inside the AI assistant your team already uses. Request access.