Color fastness refers to a textile's resistance to fading or color transfer during washing, light exposure, or other processes. It is important to test dyed or printed fabrics for color fastness using standardized methods. These include using a xenotester to test light fastness, a wash wheel to test washing fastness, and a crock meter to test rubbing fastness. Perspiration fastness is tested using a perspirometer. Test results are evaluated using grey scales to rate the degree of color change or transfer on a scale of 1 to 5. Proper evaluation of color fastness helps ensure textiles maintain their color as intended for the customer.

1. Presentation by:-
Rashmi.R
1st MHSc (TAD )

2. 
Assessment of Color
Fastness in Textiles

3.  Fastness is the resistance of a textile material to
specific chemical agencies. Poor color fastness in
textile products is a major source of customer
complaint. The fastness of a color can vary with the
type of dye, the particular shade used, the depth of
shade and how well the dyeing process has been
carried out. Dyes can also behave differently when in
contact with different agents, for instance dyes
which may be fast to dry-cleaning may not be fast to
washing in water. It is therefore important to test
any dyed or printed product for the fastness of the
colors that have been used in its decoration.
Fastness

4. 
Colorfastness
A distinction should be made between
dyeing(internal pigmentation) and
printing(external pigmentation). The buyer has a
right to expect dyed fabrics to withstand the
deterioration elements or influences to which the
finished cloth will be subjected such as:-
Sunlight Perspiration Washing Friction

5. 
Evaluation of fastness properties of
a dye is done by measuring:-
Washing-
Wash Wheel
Light-
Xenoster
Rubbing -
Crock meter
Perspiration-
Perspirometer
Evaluation of Fastness
Properties

6. 
Fastness To Sunlight

XENOMETER
XENOSTER
•This is used to test the light fastness of
the dyed fabric.
•color fastness to light, By Xenotester

7.  Commercial testing agencies frequently use standard
tests to light fastness specially designed powerful carbon
arc lamp has the same effect as that of sunlight. Samples
to be tested revolved around this lamp for definite period
of exposure.
 After processing, comparison in the change in color of the
specimen with the changes that have occurred in the
standard pattern under suitable illumination is carried
out to determine the fastness of light.
Function of Xenometer

8. The best way in which to determine fastness to
launder a fabric.
A10 x 4 cm swatch of the dyed fabric is taken and is sand
wiched between two adjacent fabrics and stitched.
The sample and the adjacent fabric were washed together.
Five different types of washing are specified as different
washing methods.
•The solution should be preheated to the required temperature of washing.
After soaping treatment, the specimen is removed, rinse twice in cold water ,
Squeezed and dried in air at a temperature not exceeding 60°C. the value is
evaluated with the help of grey scales.
Fastness to Laundering

9.  Features of Washing Fastness Tester:-
 •It is fabricated out of quality stainless steel.
 •Possess electric heater to heat water in water bath.
 •The microprocessor based programmer is provided
for temperature control.
 Buzzer to indicate the completion of the process cycle
or step.
WASH FASTNESS

10. 
WASH FASTNESS TESTER

11. 
FASTNESS TO RUBBING
 The test is quite:-
Sensitive and for getting consistent result, it
is necessary to use
 Standard crock meter
 Cloth,
 Maintain uniform pressure for applying
rubbing strokes and number of strokes.

12. 
Crock meter is used for testing the transference of color
from the surface of one material to another by either wet or
dry rubbing.

13. 
In this there are
two types of
Crocking:-
Dry crocking:-
A 2” square of
colored fabric
rubbed against a
piece of white
sheeting. Any
discoloration of
the fabric itself,
the color is not
fast to dry
crocking.
Wet crocking:-
A piece of white
sheeting should
be dampened and
rubbing against
the piece of
untested colored
fabric. Any
discoloration of
the white cloth
should be noted.
If this occurs, the
color is not fast to
wet crocking.
COLOUR FASTNESS TO RUBBING

14. 
Fastness to perspiration
 •The fastness of colored fabric with reference to alkaline and ac
idic perspiration was evaluated. For the alkaline (pH‐8) and aci
dic (pH‐5.5) liquors were prepared and the composite specimen
s were dipped in acidic and alkaline solution separately for 30
minutes. Good and uniform penetration of the solution was ens
ured. The liquor was poured off and the excess water and air b
ubbles, if any were removed by passing the specimens in betwe
en two glass rods. Composite specimens were then placed bet
ween glass/acrylic plates with a pressure of 12 kpa per
spirometer.
 The perspirometer,was kept for four hours at a temperature of 37 (
±20C). Afterwards, the fabrics were removed, separated and drie
d in air below 60°C. The values were rated as per the grey scale. T
he details of the values assigned for these properties are:

15. 
 •5 =Negligible (Excellent)
 •4 =Slightly changed (Good)
 •3 =Noticeable changed (Fairly good)
 •2 =Considerably changed (Fair)
 •1 =Much changed (Poor)
The values were rated as per the grey scale. The details of
the values assigned for these properties are:-

16. 
Perspirometer

17. 
There are two
types of
pressing:-
Hot pressing Wet pressing
Color fastness to Pressing

18. 
Hot pressing

19. 
 Soak the test specimen and a piece of cotton adjacent
fabric in distilled water and squeeze it to maintain
100% pick up.
 Place the soaked cotton fabric on top of the dry test
specimen and repeat
Wet pressing

20. 
COLOUR FASTNESS
ASSESSMENT BY USE
OF GREY SCALE

21. 
A different set of grey scales is used for measuring staining. Fastness
rating -5 is shown by two identical white samples and rating 1 shows
a white and a grey sample.
The other numbers show geometrical steps of contrast between white
and a series of greys. A piece of untreated, unstained, undyed cloth is
compared with the treated sample that has been in contact with the
test specimen during the staining test and a numerical assessment of
staining is given.
A rating of 5 means that there is no difference between the treated
and untreated material. If the result is in between any two of the
contrasts on the scale, a rating of, for example, 3-4 is given. Sets of
grey scales, examples of which are shown in Fig: can be supplied by
the British Standards Institution.

23. 
References:-
Wingate Isabel Barnum and Mohler, Textile Fabrics
and their selection Book,1984 , New Jersey, page
(187-192).
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24. THANK
YOU…………