What Denim Fabric Inspection Is
Fabric inspection is a check carried out on the cloth itself, before any garment is cut. The inspector unrolls each roll or a defined sample of rolls over a lit inspection frame, looks at the face of the fabric as it moves, marks defects and records them on a report. The aim is to find faults that will cause garment defects, measure how many there are and decide whether the roll is usable.
Garment inspection looks at finished products and is covered in our jeans quality inspection checklist and AQL inspection guide. Fabric inspection comes first and is usually cheaper than finding the same problem after sewing, because a faulty metre of cloth costs far less than a faulty pair of jeans. It is a different check from fabric testing, which measures properties such as strength and shrinkage, and which is covered in the denim fabric testing guide.
Why Buyers Use the Four-Point System
Without a scoring system, fabric quality becomes an argument. One side says the roll has "a few faults", the other says "a lot". A points system replaces opinion with a number, applied the same way across rolls and suppliers. The four-point system is widely used in the apparel trade, and other systems exist, including a ten-point system and customer-specific methods. Because versions differ in details, the safest course is to write the system you are using into the order, together with the limit.
The principle is simple. Defects are scored according to their length, because a longer fault wastes more fabric and is more likely to land in a visible place. The scores are added up, standardised by the area inspected and compared with an acceptance limit.
How Four-Point Scoring Works
In the commonly quoted version, each defect receives between one and four points according to its size along the length or width of the fabric, whichever is longer. A larger defect scores more, and the maximum for any single linear yard is four points, however many defects it contains. Holes are normally scored by diameter. The scale below follows the commonly used inch-based version. Confirm the exact scale with your supplier or inspection company before you adopt it, as variations and metric versions exist.
Inspection is normally carried out with the fabric passing over a lit frame at a controlled speed, with lighting that shows weave faults and shade variation. The inspector marks each defect and records its position, type and score. Defects that run the full width, such as weft bars, are scored as severe because they affect every garment cut from that section.
Calculating Points per 100 Square Yards
The raw point total is not comparable between rolls of different length and width, so it is converted into points per 100 square yards. The formula is the total points multiplied by 36 and by 100, divided by the length inspected in yards multiplied by the fabric width in inches. For illustration, take a roll with the following figures, which are invented to show the arithmetic.
| Item | Illustrative figure |
|---|---|
| Length inspected | 100 yards |
| Usable fabric width | 58 inches |
| Total points recorded | 18 |
| Calculation | (18 x 36 x 100) divided by (100 x 58) |
| Result | about 11.2 points per 100 square yards |
The same roll would score higher if its width were narrower or if the same points occurred in a shorter length. Factories that work in metres use a metric version of the formula, so make sure both parties use the same one and the same width, either full width or usable width. If the width is quoted inconsistently, the scores will not match.
Common Denim Fabric Defects
Denim has its own set of faults, linked to the yarns, the indigo dyeing, the weaving and the finishing. Knowing them helps you read an inspection report and ask sensible questions.
Slub deserves a special mention. In slub denim, irregular thick places are the design and should be agreed in the standard, not scored as defects. A fabric that is meant to be uniform but shows slubs is faulty. Our types of denim fabric guide explains the families. Skew and bowing, where the weft runs off the square, show up as twisting legs after washing and are linked to the finishing process and to the points in the denim shrinkage guide.
Some defects are hard to see on greige or unwashed cloth and only appear after washing. If your garments receive a heavy wash, ask whether the inspection is done on the fabric as supplied, and consider a wash test on a sample cut from the roll when the construction is new or the shade is critical. Indigo streaks and weft bars are common examples of faults that become more obvious after a wash.
Shade Grading and Shade Bands
Even a good roll may differ in colour from the next one. Denim is dyed in batches, and slight differences appear between dye lots and sometimes within a roll from one end to the other, or from the edge to the centre. A pair of jeans cut from two different shades looks wrong, even when each piece alone is acceptable.
Shade grading deals with this by sorting rolls into groups or bands that are close enough to cut together. Each band is cut and sewn together as a lot, so garments within a lot match, and the lots are then identified on cartons. The inspector compares each roll to an approved reference under a defined light, assigns a grade or band and records it. For a pair with a strong wash effect, the fabric shade interacts with the wash, so the approved reference should be the washed garment as well as the fabric. See denim colour fastness and the guide to indigo and black dyeing for how dyeing affects shade, and the coloured and white jeans guide for pale shades where variation is easiest to see.
Setting Acceptance Limits
The score alone is not a decision. The limit is a commercial agreement between you and the supplier. In general terms, a stricter limit means a higher fabric price and more rejected rolls, and a looser one means more waste at cutting and more garment defects. Premium and pale products usually need stricter limits than mass-market dark denim. Our recommendation is to set the limit with the supplier at the start of development, write it into the specification, and confirm it on a sample roll so both sides know what it looks like.
Commonly quoted limits differ between buyers and sectors, so there is no single right figure. A practical approach is to agree three outcomes for a roll: accept, accept with defects marked and cut around, and reject. Decide in advance what happens to a rejected roll, whether it is replaced, credited or downgraded, and who pays for inspection. Link these outcomes to the denim sourcing terms agreed with the mill.
- Faults found before the fabric is shipped and paid for
- Replacement or credit is simpler to arrange
- Needs trained inspectors or a third party at the mill
- Fabric can still be stored and handled before cutting
- Checks the fabric that will actually be cut
- Catches transit damage and storage marks
- Claims against the mill are harder and slower
- Often combined with a wash and shrinkage test
How Much Fabric to Inspect
Inspecting every metre of every roll is thorough but slow and expensive. Many buyers inspect all rolls for a new or critical fabric and a sample of rolls for a proven, repeated fabric. Others inspect a percentage of each lot, with a rule to inspect more if the first results are poor. The right amount depends on how much risk the fabric carries: a new mill, a pale colour, a stretch fabric or a washed finish deserves more inspection than a repeat order of a stable dark indigo.
Whatever the sample size, record which rolls were checked. A report that says "fabric inspected" without roll numbers cannot be used in a dispute. Link the results to the garment production plan: if the inspection finds many marked defects, the marker plan has to cut around them, which changes the consumption and the cost. The jeans costing sheet shows where fabric consumption sits in the price.
What a Good Inspection Report Shows
A report should let someone who was not there see what was found. At a minimum it contains:
- Supplier, fabric name or code, colour, lot and roll numbers.
- Length and width of each roll, inspected and stated.
- Each defect type, position and points.
- Total points and the points per 100 square yards.
- Shade grade or band for each roll and the reference used.
- The scale, standard and limit applied, and the result.
- The inspector's name, date and a note of lighting and speed.
- Photographs of significant defects and of the shade comparison.
Ask for the report before the fabric is released to cutting. If the fabric has already been cut, the report can only tell you what went wrong. The same record should be filed with the sample approvals, as described in the jeans sampling process guide.
- 1Agree the standardScale, width basis, limit and shade reference written into the order.
- 2Select the rollsAll rolls for new fabrics, a sample for proven ones, more if early results are poor.
- 3Inspect and scoreMark defects, score each one and note shade against the reference.
- 4Grade the shadeSort rolls into bands that can be cut together.
- 5Decide and recordAccept, accept with marked defects, or reject, with the report filed.
Common Fabric Inspection Mistakes
- Not agreeing the scale. Different versions give different scores for the same roll.
- Mixing full width and usable width. The points per 100 square yards will not match.
- Inspecting under poor light. Weft bars and shade shifts are easy to miss.
- Ignoring shade bands. Panels cut from different shades end up in the same pair.
- Inspecting after cutting. Defects are then in the garments, not the fabric.
- Treating the score as the whole story. Strength, shrinkage and colour fastness need testing too.
- Scoring system, version and scale named in the order
- Width basis (full or usable) agreed
- Acceptance limit and actions for rejected rolls agreed
- Slub or intentional texture defined in the approved standard
- Inspection under uniform, bright lighting at a controlled speed
- Shade reference approved and held by both sides
- Shade bands recorded and carried through to cutting
- Roll numbers listed in the report with total points
- Wash test on a sample cut from the roll for critical fabrics
- Report received before the fabric is released for cutting
Denim Fabric Inspection with Ruhrose
Ruhrose builds denim fabric inspection into product development, with development in Bangladesh and UK buyer support. We help agree the scoring method, the limit and the shade reference with the mill, and the results are filed against the pre-production sample. Orders start from 500 pieces per style and colour. For choosing the mill in the first place, see denim mills in Bangladesh and how to find denim fabric suppliers. When you are ready to brief a fabric or a style, start a product enquiry.