1. introduction

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INFLUENCE OF SIZE AND DISTRIBUTION OF COLOR COMPONENTS
ON COLOR VALUES OF WOVEN FABRIC
Assoc. Prof. Krste Dimitrovski, DSc
Helena Gabrijelčič, BSc
University of Ljubljana, Faculty of Natural Science and Technology,
Department of Textiles, Ljubljana, Slovenia
Abstract: Woven fabrics simulation more or less successful presents color values of woven
fabrics on the computer screen and on the paper. The color values of woven fabrics depend on
color values of differently colored threads, fabrics is made from, and on constructional
parameters (the fineness, density and weave). They all contribute to the size and distribution of
differently colored component which make the total color appearance and color values of woven
fabric simulation. While the fineness and density of thread influence only on size of color
component, the weave is affecting both the size and distribution of color component. It is
possible to obtain different color values on woven structure only with the change of weave. The
present research work is trying to find out how big is the influence of weave on the color values
of woven fabrics simulation and consequently to a real woven fabric. In this purpose simulation
of woven structures in different weaves and with different colored threads in warp and weft
system are prepared. Color deviations between structures in different weaves are theoretically
and spectrophotometrically analyzed.
Key words: thread density, influence of weave, colour values, colour differences
1. INTRODUCTION
The colour of fabrics made of differently coloured threads is not influenced only by the colour
values of individual components – warp and weft threads and their number but also by a fabric
constructional parameters such as the warp and weft threads fineness, density and weave. The
influences of these constructional parameters on colour values of woven fabrics haven’t been
objectively determined yet, because the problem is very complex. Beside experimental
measurements the way to solve this problem is to use theoretical calculations, which are based
on geometry of interlacing point. So with analytical estimation of the influence of the threads
fineness and density, coupled with equations for determining colour differences in the CIE
L*a*b* colour space, the fractions of individual colour components in a colour repeat can be
determined relatively precisely and on that basis also its colour values. But the fact is that in such
calculations, except in the number of the warp and weft interlacing points, a weave with its
specifies never appears, as do threads fineness and density.
2. THEORETICAL PART
2.1 Basic weaves and geometrical arrangement of their interlacing points
Plain weave is the simplest and the most common weave with the smallest repeat unit. It is
characterised by the tightest and maximally possible interlacing of the warp and weft threads. All
other weaves have reduced interlacing of the warp and weft threads and larger repeat units,
Figure 1. In these weaves the agglomeration of warp and weft interlacing points increases the
size of colour components on fabric and grouping into a narrow areas with prevailing surfaces of
one colour.1
a
c
b
Figure 1: Schematic presentation of weaves with different size of repeat and agglomeration: a –
plain, b – rep 2/4 and c – basket 4/4.
2.2 Colour values of woven fabrics made of different coloured threads
The warp and weft interlacing point is made up of three different colour components: warp
thread, weft thread and the space between threads, which all contribute to the colour values of a
final fabric, Figure 2. 2
warp
weft
1
3
2
1/gw
1/go
1
3
2
dw
do
Figure 2: Schematically presentation of the density of warp and weft threads (go, gw) and warp
and weft diameter (do, dw).
Colour values of colour repeat in the weave can be calculated if taking in consideration colour
values of its colour components (warp, weft and space between threads) and constructional
parameters of woven structure (threads diameter and warp and weft density). Every single
component in one repeat has its surface, which size and shape depend on threads diameter and
density. The characteristics of components surface change with a change of constructional
parameters. As a consequence the fraction of single colour component of woven fabrics is more
or less perceivable and calculated with equation (1): 3
u n u
n
u
n
 uwn , wt  nwt , wi
(1)
Ui  on,ot ot ,oi on, wt wt ,oi  wn ,ot ot , wi
noi
nwi
where n is the number of all points in a colour repeat; uon,ot is the content of the warp thread
colour in the warp interlacing point; not,oi is the number of the warp points on i colour warp
threads; uon,wt is the content of the warp thread colour in the weft interlacing point; nwt,oi is the
number of the weft points on i colour warp threads; noi is the sum of the warp and the weft points
on i colour warp threads = not,oi+nwt,oi; uwn,ot is the content of the weft thread colour in the warp
interlacing point; not,wi is the number of the warp points on i colour; uwn,wt is the content of the
weft thread colour in the weft interlacing point; nwt,wi is the number of the weft points on i colour
wefts; nwi is the number of the warp and the weft points on i colour wefts = not,wi+nwt,wi.
Colour differences between standard fabric and pattern are then calculated by using the
following equation: 3,4
n
n
n
i 1
i 1
i 1
E * ab  ( (a * iU i )  a * s ) 2  ( (b * iU i )  b * s ) 2  ( ( L* iU i )  L* s ) 2 (2)
where a*v, b*v and L*v are colour values of the pattern; a*s, b*s and L*s are the colour values of
the standard fabric; a*i, b*i and L*i are the colour values of i component; Ui is the content of i
component in a colour repeat.
3. EXPERIMENTAL PART
Computer simulations of seven different weaves were prepared by using the Arahne CAD
system. 5 All weaves were chosen with the same ratio between the number of warp and weft
interlacing points on the face side and identical constructional parameters: plain-1, rep 2/4-2, rep
2/8-3, twill 4/4-4, basket 4/4-5, twill 8/8-6 and basket 8/8-7. The warp threads of pattern are red,
weft threads are yellow and the foundation is white with L*, a*, b*, C*ab and hab colour values
given in Table 1.
Table 1: Measured L*, a*, b* and calculated C*ab, hab colour values of red warp thread, yellow
weft thread and white foundation.
Colour value
L*
a*
b*
C*ab
hab ()
Warp-red
Weft-yellow
47,18
57,65
17,49
60,24
16,87
Foundation-white
84,71
-7,29
69,69
70,07
95,97
94,16
4,14
-11,20
11,94
290,29
Three groups of simulation were constructed:
- group A with constant warp and weft thread fineness 30 tex and density from initial 30
threads/cm with the reduction of 10 % to 27 threads/cm;
- group B with constant warp and weft thread fineness 20 tex and density from initial 40
threads/cm with the reduction of 10 % to 36 threads/cm;
- group C with constant warp thread fineness 20 tex and weft thread fineness 40 tex and
density from initial warp density 40 threads/cm with the reduction of 10 % to 36 threads/cm
and initial weft density 20 threads/cm with the reduction of 10 % to 18 threads/cm.
The fractions of individual threads and of foundation reflectance were determined by calculation
on the basis of constructional parameters, which are presented in Table 2. With the help of
colour values of warp and weft threads and fractions of colour component (Uo-warp, Uw-weft,
Uf-foundation) the theoretical colour values L*, a*, b*, C*ab and hab of different weaves were
calculated.6,7,8 Colour values of the obtained surfaces were measured with the Spectrolino
SpectroScan spectrophotometer of GretagMacbeth. Light source was D65.
Table 2: Constructional parameters of fabric and calculated fractions of the warp and weft
threads and the space between the threads (foundation) for pattern 1 to 7.
Group
A
B
C
Pattern
1-7
1-7
1-7
1-7
1-7
1-7
Warp
go
30
27
40
36
40
36
do (mm)
0,304
0,304
0,248
0,248
0,248
0,248
Weft
Uo
0,496
0,484
0,4997
0,494
0,644
0,611
gw
30
27
40
36
20
18
dw (mm)
0,304
0,304
0,248
0,248
0,351
0,351
Fund.
Uw
0,496
0,484
0,4997
0,494
0,354
0,350
Uf
0,007
0,032
0,0006
0,0115
0,0024
0,0395
Cover
factor
0,992
0,968
0,9994
0,989
0,998
0,961
Finally, colour differences E*ab were defined by means of equations (1) and (2) between plain
weave taken as standard and other weaves.
4. RESULTS OF MEASUREMENTS
In the Table 3 and on Figures from 3 to 5 theoretically calculated and measured colour values
L*, a*, b*, hab, C*ab and colour differences E*ab between plain weave-1 and other weaves 2-7
are presented. Patterns are plain - Pl, rep 2/4-Re2/4, rep 2/8-Re2/8, twill 4/4-Tw4/4, basket 4/4Ba4/4, twill 8/8-Tw8/8 and basket 8/8-Ba8/8. Index c and hatched line means calculated and
index m and full line means measured.
Table 3: Calculated and measured colour values L*, a*, b*, hab, C*ab and colour differences
E*ab between plain weave and other weaves of fabric groups A, B and C in different densities
and fineness.
Group
Density
(thr/cm)
Fineness
(tex)
Measured
Col.
value
Calcul
Pl
Re 2/2
Re 2/8
Tw 4/4
Ba 4/4
Tw 8/8
Ba 8/8
all
weaves
Tto=30
Ttw=30
go=30
gw=30
L*
a*
b*
C*ab
hab ()
E*ab
66,16
24,52
43,17
49,64
60,40
61,97
30,31
36,69
47,59
50,44
0,00
62,00
29,14
37,71
47,66
52,30
1,55
62,15
27,43
38,50
47,27
54,53
3,40
63,04
26,27
40,09
47,93
56,77
5,39
63,69
26,19
40,16
47,95
56,89
5,66
64,79
24,36
42,05
48,60
59,91
8,49
65,93
21,71
43,88
48,96
63,68
11,89
Tto=30
Ttw=30
go=27
gw=27
L*
a*
b*
C*ab
hab ()
E*ab
66,85
24,02
41,84
48,24
60,14
63,36
28,16
37,02
46,51
52,74
0,00
63,26
29,08
37,69
47,60
52,34
1,15
53,06
28,26
37,42
46,90
52,94
10,32
64,80
25,68
39,45
47,07
56,93
3,75
63,73
27,36
38,27
47,04
54,44
1,53
65,35
24,82
40,48
47,48
58,49
5,20
63,92
26,19
38,51
46,57
55,78
2,53
Tto=20
Ttw=20
go=40
gw=40
L*
a*
b*
C*ab
hab ()
E*ab
65,95
24,68
43,59
50,09
60,48
60,38
33,21
34,86
48,14
46,39
0,00
61,48
31,64
36,09
47,99
48,76
2,28
61,69
30,45
37,16
48,04
50,67
3,83
63,33
24,98
40,46
47,55
58,30
10,38
63,46
26,04
39,77
47,54
56,78
9,22
67,45
18,43
46,74
50,24
68,48
20,24
67,20
18,98
45,03
48,87
67,14
18,77
Tto=20
Ttw=20
go=36
gw=36
L*
a*
b*
C*ab
hab ()
E*ab
66,27
24,44
42,96
49,43
60,36
61,19
32,65
34,81
47,73
46,83
0,00
60,86
32,65
34,53
47,52
46,60
0,43
61,44
30,55
35,24
46,63
49,08
2,16
62,23
27,05
37,82
46,50
54,43
6,45
63,04
29,05
37,84
47,70
52,48
5,05
63,92
24,67
39,97
46,97
58,31
9,89
63,68
26,49
38,81
46,99
55,69
7,76
Tto=20
Ttw=40
go=40
gw=20
L*
a*
b*
C*ab
hab ()
E*ab
60,57
33,90
35,89
49,37
46,63
57,19
39,63
28,90
49,05
36,10
0,00
56,80
39,06
29,00
48,65
36,60
0,70
56,69
38,53
28,88
48,15
36,86
1,21
58,66
34,90
32,64
47,78
43,08
6,20
59,66
33,14
33,03
46,79
44,91
8,08
60,39
30,89
34,83
46,55
48,44
11,04
58,98
34,29
32,38
47,16
43,36
6,62
Tto=20
Ttw=40
go=36
gw=18
L*
a*
b*
C*ab
hab ()
E*ab
62,16
32,21
34,62
47,29
47,06
59,15
35,78
30,48
47,01
40,43
0,00
58,54
36,94
29,74
47,42
38,84
1,50
58,67
36,22
30,15
47,12
39,77
0,73
59,69
33,75
32,45
46,82
43,88
2,88
59,95
34,75
31,86
47,14
42,51
1,90
60,17
32,16
33,08
46,14
45,81
4,57
60,67
32,33
33,49
46,55
46,02
4,83
A
B
C
Tto=30, Ttw=30, go=30, gw=30
L*m
C*m
75,00
L*c
C*c
Tto=30, Ttw=30, go=27, gw=27
a*m
hm
a*c
hc
b*m
b*c
Colour values
65,00
55,00
45,00
35,00
25,00
15,00
Pl
Re2/4 Re2/8 Tw 4/4 Ba4/4 Tw 8/8 Ba8/8
Weave
Pl
Re2/4 Re2/8 Tw 4/4 Ba4/4 Tw 8/8 Ba8/8
Figure 3: Calculated-c and measured-m colour values L*, a*, b*, hab, C*ab of group A.
Tto=20, Ttw=20, go=40, gw=40
L*m
C*m
75,00
L*c
C*c
Tto=20, Ttw=20, go=36, gw=36
a*m
hm
a*c
hc
b*m
b*c
Colour values
65,00
55,00
45,00
35,00
25,00
15,00
Pl
Re2/4 Re2/8 Tw 4/4 Ba4/4 Tw 8/8 Ba8/8
Weave
Pl
Re2/4 Re2/8 Tw 4/4 Ba4/4 Tw 8/8 Ba8/8
Figure 4: Calculated-c and measured-m colour values L*, a*, b*, hab, C*ab of group B.
Tto=20, Ttw=40, go=40, gw=20
L*m
C*m
75,00
L*c
C*c
Tto=20, Ttw=40, go=36, gw=18
a*m
hm
a*c
hc
b*m
b*c
Colour values
65,00
55,00
45,00
35,00
25,00
15,00
Pl
Re2/4 Re2/8 Tw 4/4 Ba4/4 Tw 8/8 Ba8/8
Weave
Pl
Re2/4 Re2/8 Tw 4/4 Ba4/4 Tw 8/8 Ba8/8
Figure 5: Calculated-c and measured-m colour values L*, a*, b*, hab, C*ab of group C.
5. DISCUSSION
5.1 Influence of constructional parameters on fractions of warp, weft and foundation
In experimental work three groups of fabric simulations were constructed. In group A the initial
fabric has the same number of fineness and density in both threads systems 30 tex and 30
threads/cm. With such construction the cover factor of a fabric is 0,992 and the foundation
influences is nearly negligible with the fraction 0,007. In group B the difference between warp
and weft fineness and density of initial fabric is high. The influence of low warp and weft
fineness of 20 tex fineness is substituted with high threads density 40 threads/cm, but cover
factor is remaining high 0,9994 and the foundation fraction is less than 0,1%. In the third casegroup C, the difference between warp and weft fineness is of 20 tex and the between warp and
weft density 20 threads/cm. Low warp fineness 20 tex is substituted with high warp density
40/cm, and low weft density is substituted with high weft fineness 40 tex. But as the change of
fineness can’t influence on construction as the change of density, the fractions of warp and weft
threads differ from each other and they are: Uo=0,644, Uw=0,354, but cover factor remains high
0,998. The density of initial woven structure of each group than changes for 10%, and the
influence of this change is observed on colour values of simulations.
5.2 Influence of weave on colour values at different densities
Figures 3, 4 and 5 are presenting the curves of the calculated and measured colour values of
simulations from groups A, B and C in different weaves and densities. It is evident that the
colour values L*, a*, b*, hab and C*ab change differently with the change of the weave from plain
through rep 2/4 and 2/8 to twill 4/4, basket 4/4 and twill 8/8, basket 8/8. It can be observed, that
influence of weave depends on warp and weft thread density and fineness.
The changes of colour values from weave 1 to 7 are different in groups A, B and C, due to
different constructional parameters of initial simulations. In generally patterns of group A have
the highest lightness, patterns of group B are the most reddish (highest a* values) and patterns of
group the most yellowish (the highest b* values), Table 3. The influence of weave is the most
obvious by the patterns of group B, where the difference between fineness and density is very
high and E*ab values between plain and other weaves are from 2,28 to 18,77 by twill 8/8. In
this group is the most evident the similarity of patterns with the same numbers of warp and weft
points in one colour repeat. This is shown in Figure 4, where twill 4/4 and basket 4/4 have
similar colour values and the same is with twill 8/8 and basket 8/8. The influence of weave is
lower by simulations of group A, where density and fineness are numerically equal and E*ab
values between weaves reach 11,89 by basket 8/8. The lowest influence of weave and the lowest
E*ab values are by C group, where small influence of one constructional parameter is
substituted with higher influence of other constructional parameter in a thread system and colour
differences are from 0,70 up to 11,04 by twill 8/8.
In all three cases lightness L* is a little increasing when the weave changes. Yellow colour
parameter +b* is increasing too and red parameter +a* is decreasing. So in all cases different
disposition of interlacing points by twill 4/4 and basket 4/4 with 8 warp and weft points in weave
repeat and twill 8/8 and basket 8/8 with 32 warp and weft points in repeat, brings to higher
lightness L* and yellow value +b*. These weaves look lighter with more yellow. Moreover, it
seems that with agglomeration of red and yellow interlacing points on the surface, the influence
of yellow colour is higher in comparison with red colour and the consequence is increasing of
lightness and parameter b* by weaves with 4 or more agglomerated points. But from Table 1 it
can be seen also that a* value of red thread is 57,65 and of yellow negative –7,29 and b* value of
red is 17,49 and yellow 69,69. So the values b* sum up with the change of weave and points
agglomeration, but the values a* subtract because of negative –a* value of yellow thread.
Consequently the changes in hue-hab values are very high in basic fabrics in all three groups,
because of the relationship hab= arc tg (b*/a*).
With reduction of warp and weft threads density, the fractions of warp and weft threads and
cover factor reduce as well. By threads density 27 threads/cm in group A the warp and weft
fractions are 0,484 and cover factor is 0,968, by density 36 threads/cm in group B are Uo= Uw=
0,494 and cover factor is 0,989 and in group C by density go=36 and gw=18 the fractions are Uo=
0,611 and Uw= 0,35 and cover factor 0,961. By these constructional parameters the influence of
weave on colour values of simulations is smaller, what can be seen on right sides of Figures 3, 4
and 5, where the curves are more regular and the values of colour differences E*ab between
weaves are lower, Table 3.
5.3 Differences between calculated and spectrophotometrically measured colour values
On Figures from 3 to 5 are presented theoretically calculated colour values as hatched straight
lines and measured colour values as full curves for simulations of groups A, B and C. The ratio
between the number of warp and weft interlacing points and warp and weft fractions are equal
for all presented weaves and in consequence the theoretically calculated colour values are equal
for all weaves too. But spectrophotometrical determination finds out that different weaves show
quite a big colour differences in all colour values, so disposition and agglomeration of interlacing
points influence on colour measurements.
Colour measurements considerably differ from theoretical calculation in the case of group B,
where patterns have high threads density and very low fineness, above all in colour parameters
a*, b* and consequently hab. Theoretical calculations predict all colour values better in the case
of group A and especially in group C, so, when threads fineness and density are of same number
or when low density is substituted with high fineness or vice versa. However the differences are
still the biggest in colour parameters a*, b* and hab and nearly insignificant in colour parameter
C*ab. This can be observed in smaller colour differences between calculated and measured values
in Figures 3-group A and 5-group C.
Deviations between calculated and measured colour values become smaller with a reduction of
density of 10% in all three groups. Here the cover factors of fabrics are smaller and for group A
is 0,968, B 0,989 and group C 0,961 in comparison with initial A 0,992, B 0,9994 and C 0,998.
Moreover with a reduction of threads density there is a bigger influence of foundation
reflectance, which is white. Apart from lower colour differences between weaves, bigger
foundation reflectance causes lower differences between calculated and measured colour values
and so, better colour prediction for these constructional parameters.
6. CONCLUSIONS AND FURTHER RESEARCHES
The influence of different weaves on colour values of fabric simulations at different threads
density is investigated in the experimental work. It is found out that by agglomeration of threads
on the fabric surface, i.e. by increasing of individual colour areas in a particular colour repeat
(threads grouping), the colour values L*, a*, b*, hab and C*ab change differently in dependence
on the colour of the warp and weft threads and the relation between fabric density and fineness
(group A, B and C):
- threads fineness and density influence on fractions of warp, weft, foundation and fabrics
cover factor and with their change the influence of constructional parameters on colour
values of woven fabrics can be achieved;
-
-
-
-
-
-
predicted colour values of weaves with the same relation between number of warp and weft
interlacing points are the same, although the constructions of these weaves are very different,
but spectrophotometrically colour deviations between different weaves are high, because of
different dispositions and agglomeration of interlacing points on fabrics surface;
with the reduction of fractions Uo, Uw and Uf and cover factor, their influence on colour
values of fabric is reduced too, and at the same time there are not such colour differences
between different weaves;
the influence of weave is bigger in the patterns with higher density in both thread system and
in the patterns, which have big numerical difference between threads fineness and density
(group B), with the decrease of density the influence of different weaves on colour values is
reduced;
the biggest deviations between different weaves occur in values, which determinate the hue
of a surface, that are values a*, b* and hab, but on the other hand the change of weave play
almost no role on values of C*ab and L*, not regarding the density;
theoretical calculations of colour values match better spetrophotometrically determined
values by patterns with lower density, where the cover factor is smaller and the foundation
reflectance in higher;
the comparison of calculated and measured colour values at changing density indicates that
in some weaves at certain density colour values can be better theoretically predicted.
During the further researches in this field the experimental work could be enlarged on other
weaves too and detailed investigation of increasing or decreasing, grouping and agglomeration of
interlacing points should be done. Consequently, this would provide analysis of deviations
between the calculated – theoretically and spectrophotometrically determined colour values and
the reason for such deviations.
7. REFERENCES
1
Božič, P. (2002). Vpliv vezave na barvne vrednosti tkanin iz različno obarvanih niti,
Diplomsko delo, Univerza v Ljubljani, Naravoslovno tehnična fakulteta, Oddelek za tekstilstvo,
Ljubljana
2 Dimitrovski, K. & Gabrijelčič, H (2001). Izračunavanje i mjerenje boja tkanina iz različito
obojenih niti, Tekstil, Vol. 50, No. 11, November 2001, pp. 558-567
3 Dimitrovski, K & Gabrijelčič, H. (2002). Napovedovanje barvnih vrednosti žakarskih tkanin =
Predicting of colour values of jacquard fabrics. Tekstilec, Vol. 45, No. 7/8, pp.179-194., ISSN
0351-3386
4 Mc Donald, R. (1997). Colour Physic for Industry, Society of Dyers and Colourists Bradford,
(2nd ed.), England
5 Arah Weave 3.2 User’s Manual 1993-2002 Arahne. Available from: http//www.arahne.si
Accessed: 2002-01-15
6 Kožuh, M. (2002). Vpliv gostote in finosti na barvne vrednosti tkanin iz različno obarvanih
niti, Diplomsko delo, Univerza v Ljubljani, Naravoslovno tehnična fakulteta, Oddelek za
tekstilstvo, Ljubljana
7 Kysselef, I. (2002). Vpliv gostote na barvne vrednosti tkanin iz različno obarvanih niti,
Diplomsko delo, Univerza v Ljubljani, Naravoslovno tehnična fakulteta, Oddelek za tekstilstvo
8 Bregar, N. (2002). Vpliv finosti na barvne vrednosti
tkanin iz različno obarvanih niti,
Diplomsko delo, Univerza v Ljubljani, Naravoslovno tehnična fakulteta, Oddelek za tekstilstvo,
Ljubljana
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