Lightfastness of Different Types of Dyes

fiber reactive dyes, acid dyes, and direct dyes

Answers on this page to questions about lightfastness of dyes:

What is lightfastness?
Can fading be prevented by using a UV protector?
What should be done to slow light damage to dyed materials?
Can anything else reduce fading from visible light?
Does Retayne add to lightfastness?
Which dyes are more or less lightfast? (tables including reactive dyes, acid dyes, etc.)

What is lightfastness?

Lightfastness is the degree to which a dye resists fading due to light exposure. Different dyes have different degrees of resistance to fading by light. All dyes have some susceptibility to light damage, simply because their strong colors are indications that they absorb the wavelengths that they don't reflect back. Light is energy, and the energy that is absorbed by pigmented compounds may serve to degrade them or nearby molecules. (For a detailed look at how certain Basic type dyes can cause damage when exposed to light, see my doctoral dissertation, DNA Damage and Cell Lethality by Photodynamically Produced Oxygen Radicals.)

Can fading be prevented by using a UV protector?

Unfortunately, ultraviolet is not the only kind of light that causes damage. Visible light is quite sufficient to fade colored materials. In tests using a UV protectant, DyersLIST members Jerry Trapp and Sally Holmes found that the beautiful but poorly lightfast blue-violet, Procion type blue MX-7RX, actually showed an increased amount of damage. This was presumably caused by an interaction between the protectant and the dye; UV protectants in glass windows will surely do no harm, whether or not they are helpful. Most likely, UV protection will help protect some dyes, but not others.

Reportedly, a spray product called Quiltgard can provide partial protection in some cases. This product washes out and must be reapplied after every cleaning. The effectiveness of this product in preventing fading should be tested for each individual dye used in an important or valuable project, to be certain that it does not accelerate fading instead of preventing it. To do this test, take dyed scraps of fabric and treat one of each color with Quiltgard, while leaving another untreated. Label the swatches carefully, and expose to direct sunlight or a commercial lamp of the type used for testing lightfastness.

What should be done to slow light damage to dyed materials?

To extend the lifetime of dyed items, machine dry or drip dry indoors, instead of line-drying outdoors, and store in darkness when not in use.

When possible, substitute a more lightfast dye for one that is less lightfast.

Can anything else reduce fading from visible light?

In some cases, especially those dyes I studied in graduate school, oxygen is required for the damaging reactions of dye chemicals that are caused by light. This is called the photodynamic effect. Therefore, items that are framed behind glass may last longer than similar items that are exposed to air. (I do not know whether dyes in other classes than the thiazine, acridine, xanthene, and phenazine dyes I studied are susceptible to the photodynamic effect; it is safest to assume that some of them may be.) The preservation of archival materials may benefit from storage under an inert gas such as nitrogen.

Does Retayne add to lightfastness?

It has been suggested that dye fixatives, such as Retayne®, may actually reduce the lightfastness of dyes somewhat. Retayne and similar products are widely used to increase the washfastness of direct dyes, and, in some cases, to substitute for adequate washing-out of excess dye after dyeing with Procion MX type dyes. For washable garments dyed with direct dyes, this effect is easily outweighed by the increased washfastness, but archival artworks should probably not be treated with such fixatives, and it is often better for individual dyers to wash out excess fiber reactive dyes, instead of using ionic fixatives, such as Retayne. (Industrial dyers may find the savings in water consumption to make the trade-off worthwhile.)

Which dyes are more or less lightfast?

The least lightfast dyes that are in use include the Basic dyes, which are noted for their brilliant colors, but are extremely light-sensitive when used on natrual fibers; they are more frequently used on synthetic fibers and also, when dissolved in alcohol, as silk paint. Acid and reactive dyes are much more lightfast. Direct dyes are not, on the whole, particularly lightfast, but there are a few direct dyes that are so lightfast that they may outperform similar shades of acid or fiber reactive dye. Vat dyes, such as indigo, may be more lightfast than other types of dyes.

Note that the washfastness tests are completely different for protein fibers such as wool, which are assumed to be hand-washed in cool water or dry-cleaned, than for cellulosic fibers, which are assumed to be laundered harshly. The washfastness tests results for Fiber Reactive Dyes show what happens when items are washed at a temperature of 205°F (96°C), a far harsher test than that used for Acid dyes, which are tested at 105°F (40°C). All fiber reactive dyes may be assumed to be far more washfast than any acid dye.

Synthetic Dyes for Natural Fibers
by Linda Knutson

The following data are best obtained from the Colour Index; however, I have drawn data from secondary sources, including assorted manufacturer's websites and Linda Knutson's valuable but out-of-print book Synthetic Dyes for Natural Fibers (LK). (See Books on Dyeing for more information on this book). For critical applications, it is best to consult your own manufacturer, or consult the Colour Index directly, as some of these numbers may not be correct. The Colour Index is published by the Society of Dyers and Colourists, and may be found in some large university's libraries.

How to Read the Following Tables

Lightfastness is judged on a scale of 1 to 8, where 8 is most fade-resistant. Washfastness is judged on a scale of 1 to 5, where 5 is most resistant to washing out. To learn which MX type fiber reactive dyes are sold under what names by your dye supplier, see Which Procion MX dyes are pure, and which are mixtures?. For acid dyes, see Which Wash Fast Acid dyes are pure?. For other fiber reactive dyes, acid dyes, and direct dyes, contact your dye supplier and ask what the colour index numbers or generic names are for your dyes; note that this is effective only for the pure dyes, as the content of the dye mixtures is a trade secret. I do not yet have the C.I. number or generic code equivalents for dyes in classes other than the fiber reactives and some acid dyes.

Reactive Dyes

Dichlorotriazine (Procion MX type) reactive dyes

c.i. number	generic name	light	washing (96°C)	perspir- ation	hypochlorite	discharge- ability	notes
Reactive Yellow 86	Yellow MX-8G	6-7	5	5	1	G	(Asian Dyes)
Reactive Yellow 86	Yellow MX-8G	4	5	-	-	-	(LK)
Reactive Yellow 22	Yellow MX-4G	5-6	5	5	1	G	(Asian Dyes)
Reactive Orange 86	Yellow MX-3R	6	4-5	4	2-3	P
Reactive Orange14	Yellow MX-4R	4-5	5	3-4	1	G
Reactive Yellow 7	Yellow MX-GR	5-6	5	4	4-5	P
Reactive Orange 4	Orange MX-2R	4	5	1	3	P
Reactive Red 2	Red MX-5B	4	4-5	3-4	1	P
Reactive Red 5	Scarlet MX-G	3-4	3-4	-	-	-	(LK)
Reactive Red 11	Red MX-8B (fuchsia)	4	4-5	3	?	P
Reactive Red 74	Pink MX-B	4-5	4-5	4	2	P
Reactive Violet 13	Magenta MX-B	4-5	4-5	3-4	3	P/F
Reactive Violet 14	Violet MX-2R	4	4	3-4	3	P
Reactive Blue 140	Turq. Blue MX-G	5-6	3-4	4-5	1	P
Reactive Blue 4	Blue MX-R	6	4-5	4-5	2	P
Reactive Blue 109	Blue MX-2G	3-4	4				(LK)
Reactive Blue 161	Blue MX-7RX	1 or 2?					(personal observation - not tested)

Vinyl sulfone (remazol) reactive dyes

c.i. number	generic name	light	washing	perspir- ation	hypochlorite	discharge- ability	notes
Reactive Yellow 37	VS Yellow GL	5	4	4	1	G	(Asian Dyes)
Reactive Yellow 160	VS Yellow 4GL	5	4	4	1	G
Reactive Yellow 42	VS Yellow FG	3-4	4	5	1	G
Reactive Yellow 15	VS Yellow GR	4-5	3-4	5	1	G
Reactive Yellow 77	VS Yellow R	4	4	4-5	1	G
Reactive Yellow 24	VS Yellow RTN	5-6	4	4-5	2	F
Reactive Yellow 17	VS Golden Yellow G	4-5	3-4	5	1	G
Reactive Orange 107	VS Golden Yellow RNL	4-5	4	4-5	1	G
Reactive Orange 16	VS Orange 3R	5	3-4	5	1	G
Reactive Red 106	VS Red C2G	3	3-4	4-5	1	G
Reactive Red 198	VS Red RB	4-5	4	4-5	1	P
Reactive Red 35	VS Red 5B	3	3B	5	1	G
Reactive Red 49	VS Bordeaux B	5-6	4	4-5	4-5	F
Reactive Violet 5	VS Violet 5R	5	4	4-5	3-4	F
Reactive Blue 203	VS Navy Blue GG	3-4	4-5	4	2-3	G
Reactive Blue 89	VS Dark Blue HR	5	3-4	4-5	1	F
Reactive Blue 28	VS Blue 3R	5-6	3-4	4-R	3-4	F
Reactive Blue 21	VS Turq. Blue G	4-5	3-4	5	3-4	F
Reactive Blue 38	VS Green 6B	6-7	3-4	4	2-3	P
Reactive Brown 18	VS Brown GR	4-5	3-4	4	1	F
Reactive Black 5	VS Black B	4?	4-5	5	1	G	a good choice for a black to discharge

Acid Dyes

[Note: the washfastness numbers for acid dyes are in no way comparable to the same numbers for other classes of dyes! The washfastness numbers here, for acid dyes, come from observations of the effects of gently washing the dyed item in cool water, at 105°F or below—only 40°C!—whereas the washfastness numbers for cellulosic fibers are for washing in water at a temperature of 205°F —96°C!]

dye	dye type	color	light	washing (40°C)	perspi- ration	milling	notes
Acid Yellow 7	(fluorescent)		1-2				ProChem Flavine Yellow G
Acid Yellow 17	(leveling acid)		6	5			(LK)
Acid Yellow 19		Bright Yellow	5	5			Jacquard 602 dichargeability: moderate
Acid Yellow 23	(leveling acid)	Lemon Yellow	4	5			(LK)
Acid Yellow 49		Jac. Yellow Sun	5-6	2-3			Jacquard 601 dichargeability: good
Acid Yellow 110		Yellow 5GN	5	5	5	5
Acid Yellow 116	(1:2 premetalized)	yellow	6-7	5			(LK)
Acid Yellow 127	(1:2 premetalized)	Brilliant Yellow	6	4-5			(LK)
Acid Yellow 219		Golden Yellow	7	5			Jacquard 603 dichargeability: moderate
Acid Orange 3		Yellow EA	4	2	2-3	2-3
Acid Orange 116		Burnt Orange	5	5			Jacquard 604 dichargeability: moderate
Acid Red 1	(leveling acid)		5	5			(LK)
Acid Red 50	(fluorescent)		2
Acid Red 52	(fluorescent)	Hot Fuchsia	2-3	3	3-4	3	Rhodamine B; ProChem 370; Jacquard 620; dischargability: poor
Acid Red 73	(leveling acid)	Scarlet	6	5			(LK)
Acid Red 88		Red A	2-3	1	3	3
Acid Red 97		Scarlet G	4	4	4-5	3
Acid Red 119		Maroon V	4-5	4-5	4-5	3
Acid Red 131		Polar Red Red 3BN	4-5	5	4-5	3	ProChem 390
Acid Red 138		Magenta	4-5	5	4-5	4/5	ProChem 338; (Itomilling)
Acid Red 151		Red F2R	4	3-4	4	3-4
Acid Red 211	(1:2 premetalized)	Bright Red	5-6	4-5			(LK)
Acid Red 213	(1:2 premetalized)	Bordeaux	7	5			(LK)
Acid Red 266		Cherry Red	6	4-5			Jacquard 617 dichargeability: moderate
Acid Red 299		Burgundy	5-6	4-5			Jacquard 610 dichargeability: good
Acid Violet 7	(leveling acid)	Magenta	4	4			(LK)
Acid Violet 17		Violet 4BS	1	2	4-5	3
Acid Violet 43		Violet	5-6	1-2			Jacquard 614 dichargeability: poor
Acid Violet 49		Violet 5BN	1-2	3	3-4	4
Acid Violet 54		Red 10B	4-5	5	4-5	5
Acid Blue 1		Patent Blue VS	2	3	3	1
Acid Blue 7	(leveling acid)	Sapphire or Turquoise	2	5			(LK) note disagreement among sources!
Acid Blue 7		Patent Blue AS	2	3-4	3	3-4	unsure where numbers came from ProChem 478
Acid Blue 7		Turquoise	1	3			Jacquard 624 dischargability: moderate
Acid Blue 9		Erioglaucine A	3	3	3	4	(Asian Dyes)
Acid Blue 9	(leveling acid)	Turquoise	1	4-5			(LK) Note disagreement!
Acid Blue 15		Blue FF	1	3	4-5	3-4	(Asian Dyes)
Acid Blue 25		Blue GR	5-6	4	3	4	ProChem 425c
Acid Blue 25		Sapphire Blue	4-5	1-2			Jacquard 622 dischargability: poor
Acid Blue 40		Blue 2GLS Bright Blue	6	2	3	3	ProChem 440
Acid Blue 45	(leveling acid)	Bright Blue	4-5	4			(LK)
Acid Blue 62		Blue 2BR	5	2-3	3-4	3
Acid Blue 62		Brilliant Blue	4	2-3			Jacquard 623 dischargability: moderate
Acid Blue 90		Brilliant Blue	1-2				ProChem 490
Acid Blue 104		Blue FFR	5	1	3-4	4
Acid Blue 113		Navy Blue 2RN	5	1	3-4	4	ProChem 413
Acid Blue 113		Navy Blue	7	4-5			Jacquard 626 dischargability: poor
Acid Blue 129		Sky Blue	4-5	4			Jacquard 621; dischargability: poor
Acid Blue 183	(1:2 premetalized)	brilliant blue	5-6	4			(LK)
Acid Blue 284	(1:2 premetalized)	Navy	6-7	4			(LK)
Acid Blue 324		Royal Blue	5-6	4-5			Jacquard 625 dischargability: poor
Acid Green 16		Green VS	3		Teal	6	4	Jacquard 631 dischargability: poor
Acid Green 101		Green GT	5	4	5	5
Acid Brown 19	(1:2 premetalized)	Brown	7	5			(LK)
Acid Brown 75		Brown ER	5	5	3	4-5
Acid Brown 85		Brown CT	3	3	3	3-4
Acid Brown 100		Brown EDR	3	3	3	3-4
Acid Brown 214		Brown RT	4	5	4	4
Acid Brown 348		Brown SR	3	3	3	3-4
Acid Brown 349		Brown SG	4	5	4	4
Acid Black 1		Black 10BX	3-4	3-4	4	3-4
Acid Black 52		Black WA	6-7	4	4-5	4-5
Acid Black 62	(1:2 premetalized)	Grey	6-7	4-5			(LK)
Acid Black 107	(1:2 premetalized)	Black	7-8	5			(LK)
Acid Black 194		Acid MSRL	7	4-5	4-5	5
Acid Black 210		Black SF	6-7	4	4-5	4-5

Food Dyes

[Note: Synthetic food dyes are all acid dyes. Their washfastness is relatively poor; do not wash textiles dyed with food colorings in warm or hot water. Their lightfastness, like that of any dye, may vary according to what textile fiber they are attached to. The numbers below reflect the lightfastness of unattached food dyes.]

name	CI #	CI name	FD & C	E. Code	Class	Light Stability	source
Tartrazine	19140	CI food yellow 4	FD & C yellow 5	E102	Monoazo	6	All Colour Supplies
Sunset Yellow	15985	CI food yellow 3	FD & C yellow 6	E110	Monoazo	4	All Colour Supplies
Erythrosine	45430	CI food red 14	FD & C red No.3	E127	Xanthene	3	All Colour Supplies
Allura Red	16035	CI food red 17	FD & C Red No.40	E129	Monoazo	5	All Colour Supplies
Brilliant Blue	42090	CI food blue 2	FD & C Blue No.1	E133	Triarylmethane	5	All Colour Supplies
Indigo Carmine	73015	CI food blue 1	FD & C Blue No.2	E132	Indigoid	3	All Colour Supplies
Fast Green FCF	42053	CI food green 3	FD & C Green No. 3	INS 143	Triarylmethane	?

Direct Dyes

c.i. number	name	light	washing	discharge- ability (neutral)	discharge ability (alkaline)
Direct Yellow 6	Yellow 3GX	3	2	4	4
Direct Yellow 11	Yellow A	4	2-3	4	4-5
Direct Orange 26	Orange SE	4	4	4-5	4-5
Direct Orange 39	Fast Orange TGLL	6-7	3	5	2
Direct Red 23	Fast Scarlet 4BS	3	3-4	4	4
Direct Red 31	Red 12B	2-3	1	3	3
Direct Red 81	Light Fast Red 5B	4-5	3	4	4
Direct Violet 9	Violet MB	2-3	2	5	5
Direct Blue 1	Sky Blue FB	2	3-4	5	5
Direct Blue 15	Sky Blue FF	2	3-4	5	5
Direct Blue 86	Fast Turq. Blue GL	6	1-2	3	2
Direct Blue 71	Light Blue FRL	5	3-4	5	5
Direct Blue 199	Blue FBL	2	3-4	4	4
Direct Black 22	Black NBR	2	3-4	4	4
Direct Black 165	Black GL	2	3-4	4	4

Vat Dyes

c.i. number	lightfastness	notes
vat yellow 1	5-6	(Yabang Group)
vat yellow 2	5
vat yellow 33	7
vat orange 1	6-7	(Richest Chemical)
vat orange 9	5-6
vat orange 2	5
vat orange 7	6-7
vat red 15	6-7	(Yabang Group)
vat red 13	7
vat red 29	6
vat violet 1	6
vat blue 1 (indigo)	5	(Trader China)
vat blue 4	7-8	(Yabang Group)
vat blue 6	7-8
vat blue 18	6
vat blue 20	7-8
vat green 1	7-8
vat green 3	8
vat green 8	7-8
vat green 13	7-8
vat brown 1	7-8
vat brown 3	7-8
vat black 8	7-8
vat black 9	7-8
vat black 25	7-8
vat black 27	7
vat black 29	6-7
vat black 38	7-8
vat brown 72	6
vat violet 9	6	(Richest Chemical)
vat black 16	6-7

Disperse Dyes

c.i. number	lightfastness
Disperse Yellow 82	3-4
Disperse Red 277	4-5

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Last updated: August 19, 2011
Page created: May 4, 2003
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