The 4-point system is the most widely used method for grading woven and knitted fabric by visual defects. It is based on ASTM D5430 and is written into many buyer and mill agreements. Each defect gets 1 to 4 points depending on its size, and the total points are converted to a score per 100 square yards so that rolls of different lengths and widths can be compared.
The points table#
| Defect length (any direction) | Points |
|---|---|
| 3 inches or less | 1 |
| Over 3 inches up to 6 inches | 2 |
| Over 6 inches up to 9 inches | 3 |
| Over 9 inches | 4 |
| Holes and openings: 1 inch or less | 2 |
| Holes and openings: over 1 inch | 4 |
Common rules:
- No more than 4 points are given for any one linear yard, however many defects it has.
- Continuous defects (such as a running barre, crease or shade change along the length) get 4 points for every yard affected.
The score formula#
The 3600 comes from 100 square yards being 3,600 square inch-yards (100 × 36).
For metric rolls, the equivalent is points per 100 square meters:
Worked example: one roll#
A roll of 120 yards with a cuttable width of 58 inches has these defects:
| Defect | Size | Points |
|---|---|---|
| Slub | 2 in | 1 |
| Slub | 4 in | 2 |
| Hole | 0.5 in | 2 |
| Oil stain | 7 in | 3 |
| Missing end | 12 in | 4 |
| Knot | 1 in | 1 |
| Total | 13 |
Score = 13 × 3600 / (120 × 58) = 46,800 / 6,960 = 6.7 points per 100 yd²
Lot results#
For a shipment, report the score for each roll and the average for the lot:
Rolls are often judged individually as well as the lot average, so one very bad roll can be rejected even if the average passes.
Acceptance levels#
Acceptance limits are set by the buyer or the fabric contract, and often differ for woven and knitted fabrics, for different fabric types, and for individual rolls versus the lot. Do not use a limit from one buyer for another buyer's order.
How to inspect#
- Sample rolls as agreed (for example, a percentage of rolls from each shade lot and supplier).
- Use an inspection frame with good overhead and back lighting, at a steady speed.
- Check width at several points and length against the ticket.
- Mark each defect with a sticker or tag at the selvedge.
- Record points, position and type on the fabric inspection sheet.
- Check shade within the roll (center to selvedge, beginning to end) and against other rolls.
- Calculate the score per roll and per lot.
What the 4-point score does not cover#
- Shade variation between rolls: handle with shade grouping and approval.
- Physical properties: GSM, shrinkage, strength and color fastness need separate tests.
- Bow and skew: measure separately. See bowing and skewing.
- Defect clusters: a low score can still hide defects concentrated in one area. Note them.
Use the four-point score formula page for a quick reference, and see fabric defects for common defect types.
Related guides#
- Final inspection: the garment inspection at the other end of the process.
- Fabric spreading: using inspection marks during spreading.
- Cutting room process: the cutting room workflow after fabric approval.
- Fabric testing standards and methods: the physical tests that complement visual inspection.