Fabric Quality Analysis Notes
Subject Overview
Fabric Quality Analysis teaches the technical calculations behind woven fabric quality — yarn count, fabric weight, cover factor, and defect identification — the analytical backbone of quality control in textile production. You'll learn yarn numbering systems and count calculations, fabric weight and GSM calculation using EPI/
Subject at a glance
4
Units
15
Topics
3
Credits
4
Infographics
Unit-wise Syllabus
4 units — open any unit for detailed topic-wise notes, diagrams and important exam questions
- Yarn numbering systems (direct and indirect)
- yarn count's effect on cost and performance
- conversion calculations
- using a pick glass to find EPI and PPI
- crimp calculation
- GSM calculation and global methods of expressing fabric weight
GSM
Weight of sample (g) / area (m²)
Crimp %
(Yarn length − fabric length) / fabric length × 100
Tex to Ne
Ne = 590.5 / tex
Denier to tex
tex = denier / 9
Thread density
EPI (ends per inch) × PPI (picks per inch)
Study guide
This unit covers yarn numbering systems (direct and indirect), how count affects cost and performance, conversions, finding EPI and PPI with a pick glass, crimp calculation and GSM and other fabric weight measures. Practise count conversions; they are common numericals.
- Warp and weft weight calculation to produce required fabric length and width
- calculating reed width and tape length
- wrap/weft cover factor definition and calculation
Warp weight (g)
(Total ends × warp length in m × (1 + crimp)) / (Ne × 1.693)
A count of 1 Ne = 1.693 m per gram
Cover factor (Ne)
EPI / √Ne
Cloth cover factor
K1 + K2 − (K1 × K2 / 28)
Reed width
Fabric width × (1 + weft crimp)
Study guide
You calculate warp and weft weights to produce a required length and width, reed width and tape length and the warp and weft cover factor. Work each calculation with units written out.
- Definition and calculation of bow and skew for woven and knitted fabrics
- weave analysis using a pick glass to derive weave
- drafting and lifting plans
- warp/weft colour patterns
Bow %
(Depth of bow / fabric width) × 100
Skew %
(Distance of skew / fabric width) × 100
Cause
Uneven tension in finishing (tentering)
Why it matters
Checks and stripes look crooked in garments
Study guide
You study bow and skew in woven and knitted fabrics and weave analysis with a pick glass to derive the weave, draft, lifting plan and colour patterns. Analyse a real fabric sample from scratch.
Defects in woven fabrics and their causes, fabric inspection systems
4-point system
Defects score 1–4 points by length
Often 40 points per 100 sq yd (buyer-specific)
10-point system
Defects score up to 10 points
Points must not exceed total yards
Common defects
Slubs, broken ends, holes, stains, shade variation
Graded by size and visibility
Study guide
You study defects in woven fabrics and their causes and fabric inspection systems. Learn the common four-point inspection approach used for export.
Why Fabric Quality Analysis Matters
Fabric analysis is how quality teams, buyers and designers check that fabric matches its specification, essential for quality control and sourcing roles.
How to Prepare for Fabric Quality Analysis
- Practise EPI, PPI, GSM and cover factor calculations on real swatches.
- Analyse unknown fabrics with a pick glass.
- Learn common fabric defects by name and cause.
Fabric Quality Analysis: Frequently Asked Questions
What is GSM?
GSM is grams per square metre, a measure of fabric weight that indicates how heavy or dense a fabric is.
What are EPI and PPI?
Ends per inch and picks per inch count the warp and weft threads in an inch of woven fabric.