Fabric Quality Control by Fabric Type: Defect and Color Control for Knitted, Denim and Woven Fabric
Knitted, denim and woven fabric can all pass through the same inspection line, but each one hides defects in its own way. In woven fabric a defect follows a direction; in knitted fabric a single needle can leave a mark along the whole roll; in denim, dark indigo hides fine defects while making shade differences obvious. That is why "looking at the fabric" is not the same job for every fabric type.
In this article we take the three fabric types one by one: what makes inspection difficult, which defects are seen most often, and how defect detection and color control are managed on the same line, from one control panel. For details on defect names, see our fabric defects guide.
Three fabrics, three different challenges
Fabric type | What makes inspection difficult | Common defects | What to check on the color side |
Woven | The defect runs along the warp or the weft; its direction points to the source | Broken end, thick pick, stop mark, reed mark | Shade variation across the width, shade drift within the roll |
Knitted | A single needle defect repeats at the same position along the whole roll; the fabric stretches | Dropped stitch, needle line, needle hole, barré | Barré becomes more visible after dyeing |
Denim | Dark indigo hides fine defects but reveals shade differences | Broken end, hole, broken pick, abrasion | Shade variation across the width (left, center, right), shade difference between rolls |
1. Woven fabric: the defect shows a direction
Woven fabric has two yarn systems, and defects usually follow one of them. A line running along the length of the fabric usually comes from the warp (broken end, reed mark), while a band running across the width comes from the weft or from a loom stop (thick pick, stop mark). The direction tells you where on the loom to look for the root cause.
At a manual inspection table, this information is often read defect by defect, from memory. Serkon.AI Q2 records each defect it detects with roll, position and type; on the live defect map, marks that repeat at the same position across the width point to the warp, while marks that run across the width point to the weft. The root-cause search starts at the loom, not at the inspection table.
2. Knitted fabric: one needle, the whole roll
Most defects in knitted fabric come from the needles, yarn feeding and machine cleanliness. A single damaged needle leaves a thin vertical line (needle line) or a series of small holes (needle hole) at the same position along the whole roll. A dropped stitch grows as the fabric is stretched, and barré, a crosswise stripe, often only becomes visible after dyeing.
In knitting, the position in the record turns directly into maintenance information: a defect that repeats at the same position shows which needle needs to be replaced. Q2 detects defects in real time on knitted structures such as single jersey, interlock and rib, and records each one in the roll's report with roll, position and type.
3. Denim: indigo hides fine defects but reveals shade differences
Denim makes inspection harder in two different ways. A fine broken end or a small hole can be easy to miss on the dark indigo surface under the inspection light. On the other hand, a slight shade difference between the left and right edges may not be visible on the line at all; it may only surface after washing or in a buyer's claim. That is why manual inspection of denim is often two separate steps: once for defects, once for shade.
Running defect detection and color control on the same line combines these two steps: Q2 detects the defects, while Colortron measures shade variation across the width (left, center, right) and shade change continuously along the roll. We explain how color measurement works in detail in our color control article.
Defects and color on one panel: Q2 + Colortron
Whatever the fabric type, the two core questions of inspection stay the same: is there a defect in the fabric, and does the color match the reference? With Serkon.AI, both questions are answered on the same line and from the same control panel.
Serkon.AI Q2 — defect detection: detects 30+ defect types in real time; records each detected defect with roll, position and type, and marks it on the live defect map. Q2 runs on woven, denim, knitted, automotive and technical textile lines.
Colortron — color control: measures at the left, center and right of the fabric width and monitors shade variation across the width (left, center, right) and shade change continuously along the roll. It measures under standard D65 light with repeatable precision up to ΔE 0.05, and every roll is lotted against its ΔE reference.
One control panel: the defect map and the color measurement are monitored on the same screen. The operator does not switch between two systems; they review detections and approve the final quality decision from one place.
Every roll leaves with its report — and the report goes to your ERP
Every roll that passes inspection leaves the line with its own report: defect list, fabric width map and defect distribution. On the color side, the roll's ΔE value and lot are included in the same record. The report is exported / integrated to your ERP, so production planning, shipping and customer reporting all read quality data from the same source. When a buyer asks "was that defect really there?", the answer is not a memory but a record with the roll, position and type.
As a plug-in on your existing inspection machine
Q2 works as a plug-in on your existing inspection machine, without changing operating habits; Colortron runs on the same line and takes over color control. Installation takes 1–3 working days after delivery, training 5–10 working days. Depending on your line speed, you can choose Q2 (50+ m/min) or Q2 Lite (up to 30 m/min). For the questions to ask when choosing a machine, see this guide.
Let the quality decision rest on data, regardless of operator or working hours.
Which fabric type should we start with on your line?
Knitted, denim or woven: tell us which fabric you inspect and how fast your line runs, and we will plan a live pre-assessment with your own fabric. You will see the results together with a defect map and a color report.
Short FAQ
Which fabric types does Q2 work on?
It runs on woven, denim, knitted, automotive and technical textile lines, and detects 30+ defect types in real time.
Are defect detection and color control done on the same line?
Yes. Q2 handles defect detection and Colortron handles color control on the same inspection line; both are monitored from one control panel.
How are the reports transferred to our ERP system?
Each roll's report (defect list, width map, defect distribution and color data) is exported / integrated to your ERP.
Do we need to replace our existing inspection machine?
No. Q2 works as a plug-in on your existing inspection machine, without changing operating habits. Installation takes 1–3 working days after delivery, training 5–10 working days.
Does inspection stop if the internet goes down?
Detection and recording run locally; if the internet drops, the line keeps running. The internet is needed for remote support, licence checks, updates and cloud reporting.
For more questions, see the 16 most frequently asked questions about AI fabric inspection.
