How fabric is dyed, printed and finished
Greige fabric goes to a process house. It is desized, scoured and bleached, often mercerised, then dyed in batches on jiggers, jets or continuous ranges, or printed by rotary screen, flatbed screen or digital inkjet. The colour is fixed by steaming or curing, the fabric is washed off, and finishes are applied: softener, resin for crease resistance, or mechanical finishes such as calendering or peaching. A stenter sets the final width and pulls the weft straight, and the fabric may be pre-shrunk before rolling.
Each step can introduce its own fault. A dye batch can differ from the next. A stenter can leave the weft curved (bow) or slanted (skew). A screen can drift out of register. Ahmedabad and Bhilwara are listed by DGFT as Towns of Export Excellence for textiles; process houses work in many other towns too.
The buyer is usually a garment maker or home-textile converter, who will cut the fabric in lays many layers deep. Shade differences between rolls, or within one roll, end up as mismatched panels in one product. That is why shade sorting matters more here than almost anywhere else.
What we check on finished and printed fabric
| Check | How it is checked | What fails |
|---|---|---|
| Shade against standard | Swatch from each sampled roll compared with the lab dip or strike-off in a light box under the agreed light source, then a second source to catch metamerism | Visible difference from the standard |
| Side-centre-side shading | Swatches from both edges and the centre of the width laid together | Edges darker or lighter than the centre (listing) |
| Roll-to-roll shade | A strip from each roll mounted on a shade card; rolls grouped into shade lots | Rolls in one shade lot that do not match; unsorted rolls |
| Bow and skew | Weft line followed across the width and its deviation measured against a straight edge, as a percentage of width | Bow or skew above the contract limit; prints or checks that run off-square |
| Print quality | Print compared with the strike-off for register, colour, sharpness and repeat joins | Misregister, missing colour, screen marks, smudges, streaks |
| Cuttable width | Width between pin marks or printed selvedge text measured along the roll | Usable width below what the marker plan needs |
| Finishing faults | 4-point grading on the frame: creases, stenter pin holes, water marks, dye spots | Points per 100 square yards above the limit |
| Rub check | Quick dry and wet rub with white cloth on dark and printed areas as a screen | Heavy colour transfer; samples sent to the lab for the formal test |
Colour fastness to washing, rubbing and light, dimensional change after washing, and restricted substances are measured by an accredited lab on sealed samples. An on-site rub or a quick wash only flags a problem.
Common defects in dyed and printed fabric
| Defect | Cause | Class |
|---|---|---|
| Wrong shade across the lot | Recipe or dye lot changed; standard not followed | Critical |
| Shade variation within a roll (ending, listing) | Uneven dyeing along the batch or across the width | Major |
| Skew or bow over the limit | Fabric fed unevenly into the stenter | Major |
| Print misregister | Screens or print heads out of alignment | Major |
| Dye spots and streaks | Undissolved dye, dirty screens, doctor blade marks | Major |
| High residual shrinkage | Fabric not relaxed or pre-shrunk | Major (from lab result) |
| Crease marks | Fabric folded or rope-dyed and not opened properly | Major or minor by visibility |
| Stenter pin holes inside the cuttable width | Pins set too far in | Minor |
| Roll tickets missing shade lot | Packing room not linked to shade sorting | Minor |
Market rules for finished fabric
- Azo dyes and restricted substances (EU). REACH Annex XVII entry 43 bans azo dyes that release listed aromatic amines above 30 mg/kg in textiles that may come into prolonged contact with skin. Printers using pigment and reactive systems should hold test reports for the colours used. See azo dyes and restricted substances.
- Prop 65 (California). Some dyes, finishes and print chemicals contain listed substances; buyers usually pass on a restricted substances list. See Prop 65.
- Care labelling (US). The FTC Care Labeling Rule covers piece goods sold to consumers for home sewing, so fabric for that trade needs care instructions.
- Flammability (US). Fabric intended for clothing falls under the Flammable Fabrics Act, and 16 CFR 1610 sets the test. Light, brushed or napped fabrics are the ones most at risk. See 16 CFR 1610.
- Certification claims. OEKO-TEX or GOTS claims on the roll ticket must match a valid certificate for that process house. See OEKO-TEX and GOTS.
Packing, transit and your purchase order
Finished fabric should travel on rolls, face in, on a firm tube, wrapped in polythene, with the shade lot written on the ticket and the outer wrapping. Rolls stored upright or stacked too high get crushed and crease. Light colours can pick up dirt from damaged wrapping, and some resin-finished fabric yellows when stored warm. The inspector checks roll tickets against the packing list and makes sure each shade lot is packed together.
Put these in your purchase order:
- Approved lab dip or strike-off, the light source for judging shade, and how many shade lots are allowed.
- Bow and skew limits, cuttable width and GSM, with tolerances.
- Fault limit in points per 100 square yards.
- Fastness grades for washing, rubbing and light, and the residual shrinkage limit, with test methods.
- Restricted substances list and certificates required.
- Roll length, packing and ticket content.
Fabric printed by hand with wooden blocks has its own page: hand block-printed textiles. Book an inspection in Ahmedabad or anywhere in India.