IN and IW methods
Yellows to browns
Yellow GCN and G, Golden Yellow RK, Scarlet R, Olive Green MW, Brown GG and G, dyed by the standard IN pad-steam or IW pad-jig method, dyeing depth 2.6 to 4.5% owf.
Textile Chemistry · Vat Dyes
Vat dyes forcotton, indigo included.
Dragonthrene vat dyes reduce, dye and reoxidise inside cotton fibre for a depth and fastness few dye classes reach. Thirty-nine shades from Yellow GCN to the sulphur vat blacks, Indigo among them, each shade with its C.I. Vat number, dyeing depth, dyeing method and fastness data.
39 shadesyellow to black, Indigo included
4 dyeing methodsIN · IW · IK · special SR
ISO 9001 · 14001certified group
30+ countriesserved since 1992
Product detail
Vat dyes across the shade card, by dyeing method and hue.
The Dragonthrene brochure lists every shade on cotton, with C.I. Vat number where it applies, dyeing depth in % owf, the dyeing method (IN, IW, IK or a special SR grade), fastness to light (xenon), washing at 95°C, rubbing dry and wet, and hot pressing.
C.I. Vat Blue 1 and Blue 5
Indigo and vat blues
Indigo (C.I. Vat Blue 1) at up to 6.0% owf and Brome Indigo (Vat Blue 5), plus Blue RSN, Dark Blue BO and VB, and the sulphur vat blues RNX and GNX.
Up to 8.0% owf
Blacks
Vat Direct Black RB and DB, Black BBRN and Sulphur Vat Black CLG, the deepest shades in the card at up to 8.0% owf, fastness to washing 4 or better across the range.
Where it goes
Cotton that needs vat-dye depth and fastness.
- Open-bath and jig dyeing of cotton woven and knitted fabric
- Indigo and sulphur vat blacks for denim and workwear
- Yarn and piece dyeing where wash and light fastness matter more than cost
- Full C.I. Vat number, dyeing method and fastness data per shade for recipe planning
Before you order
Straight answers for the technical buyer.
01What are vat dyes?
Pigments insoluble in water until reduced to a soluble leuco form in an alkaline bath. Once inside the cotton fibre, oxidation turns the dye back into its insoluble pigment form, trapped in the fibre. Dragonthrene runs 39 shades this way, from Yellow GCN to the sulphur vat blacks.
02Is indigo a vat dye?
Yes. Indigo, C.I. Vat Blue 1, is the best-known vat dye and the one denim is dyed with. Dragonthrene carries it alongside Brome Indigo and 37 other vat shades, each with its C.I. Vat number and dyeing method.
03What are vat dyes used for?
Cotton that needs to hold its colour through hard wear and repeated washing: denim, workwear, yarn and piece goods dyed by open bath or jig. Dragonthrene lists the dyeing method, IN, IW, IK or a special SR grade, alongside the fastness data for every shade.
04What is the difference between vat dyes and reactive dyes?
A reactive dye bonds chemically to the cotton fibre. A vat dye never bonds at all: it is reduced to a soluble form, absorbed into the fibre, then oxidised back into an insoluble pigment trapped there, which is why vat shades like Indigo hold up so well to washing and light. Hongda's Dragonfix range covers the reactive side; Dragonthrene covers vat.
05What dyeing methods do vat dyes use?
Open bath (exhaust) or jig dyeing, by the method marked per shade: IN and IW cover most of the card, IK and the special SR grades handle a few shades that need a different reduction. Wetting, dyeing, cold wash, oxidising, soaping and a final wash, in that order, whichever method is used.
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Textile Chemistry
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