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Original article
Patterning technique for expanding
color variety of Jacquard fabrics in
alignment with shaded weave structures
Textile Research Journal
0(00) 1–9
! The Author(s) 2014
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DOI: 10.1177/0040517514527377
trj.sagepub.com
Frankie Ng1, Ken Ri Kim1, Jinlian Hu1 and Jiu Zhou2
Abstract
This study aimed to enhance the capability of multiple weave color reproduction for Jacquard textiles. Today, the
subtractive color mixing of CMYK color system is being widely used for rendering weave patterns and assorting filling
yarn colors. However, as Jacquard color creation involves optical color mixing, the direct application of pigment mixing is
limited to corresponding to an artwork that involves red, green, blue and saturated solid black. Since Jacquard colors are
realized by opaque and non-blended material of yarns, it requires a different approach of light and pigment mixing to
simulate colors of an original image in woven forms. Therefore, in this study, the optimization of weave color reproduction was approached to properly embrace the proposed color gamut of the CMYK model in digital Jacquard textiles.
Based on the ink densities of the CMYK color scope, segmentation was applied in reflection of optical thread color
mixing to attain optimal weave patterns. A pair of primary color layers was merged by defining a set of rules to classify
individual primary and secondary color patterns to designate colored threads in associated regions, and weave structures
were designed and aligned to generate varied levels of color shades in weaving form. The correlation between shaded
weave structures and the primary color-based weave patterns were matched to present a faithful color reproduction in
weaving.
Keywords
Jacquard color patterning, region-based segmentation, extra weft figuring method, shaded weaves, gradual color
deviation
Jacquard fabric is produced by interlacing a minimum
of two sets of yarn, that is, the warp and the weft, at
right angles to each other.1 It has been developed with
delicate skills and costly labor and materials for decorative purposes. A diversity of structure formations
and color managements has been proposed for producing numerous textures and color effects. Today, digital
technologies that have been widely employed in both
Jacquard image design and production greatly enhance
production efficiency, while electronic weaving
machines, which are arranged with one end of ground
and several extra fillings, are utilized for continuous
styles. The decline of ornamental Jacquard figuring
lies in the fact that the harness needs frequent re-trials
or modifications for each design, the process of which is
often costly and time-consuming.2 The restriction on
yarn supply is considered a technical difficulty to reproduce multi-colored images in Jacquard textiles.
However, with the help of computer-aided design
(CAD) software, a number of applications have been
proposed to improve the current situation. The method
using the subtractive CMYK system succeeded in
expanding the gamut of weave color with cyan,
magenta, yellow and black filling yarns.3,4 As the
warp is fixed to a white ground, colors used in the original artwork are simulated by filling yarns.
Corresponding structures are originated from traditional shaded weaves but are reinvented to present
continuous color variations in weaving forms.
Compounding the shaded structures in layers is the
key principle to achieve seamless color gradation
1
The Hong Kong Polytechnic University, Institute of Textiles & Clothing,
The Hong Kong Polytechnic University Kowloon, Hong Kong
2
Zhejiang Sci-Tech University, Xiasha, China
Corresponding author:
Frankie Ng, The Hong Kong Polytechnic University, Institute of Textiles &
Clothing, The Hong Kong Polytechnic University Kowloon, Hong Kong.
Email: [email protected]
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effect.3–5 However, as weave patterns are directly borrowed from the auto-separated CMYK system, the
reproduced colors are restricted to red, green, blue
and saturated black. Although the primary colors of
CMYK and RGB are different, these two groups enjoy
a reciprocal relationship when their respective secondary
colors are also included. They cover a considerable
scope of displayed colors; yet, neither of them can generate an exact primary scope of the other.6 In order to
expand the creative scope of Jacquard designs, the two
primary sets are required to be properly maintained to
optimize the conditions for weave color reproduction.
Based on the concept above, this research further optimized rendering weave patterns in association of
CMYK morphology whereby the CMYK color patterns
were partitioned into CMYKRGB patterns. The principle of shaded weave structures was employed to generate numerous levels of color shades in reproduction.
The proposed design process in both color patterning
and weave structure is shown in Figure 1.
Applied theory of color patterning for
woven Jacquard textiles
The L*a*b* model describes the physical characterizes
of a color and helps eliminate the confusion created by
different reproduction characteristics. However, with
specific output devices being considered, Jacquard textiles require a color model or system applicable to
reproduction of targeted artworks. Meanwhile, the
RGB color space is widely used to define the structure
of output colors and cover a considerable range of displayed colors.7 Nevertheless, the additive theory and
the system of Jacquard fabrication are not applicable,
as colors are created by varied intensities of light
mixing. In a previous study, the CMYK system of primary sets and the auto-computed primary color layers
were directly applied to Jacquard fabrication.3,4 Yet,
modification in weave patterns is required to improve
color simulation in weaving forms. Computed CMY
layers are generally rendered on a subtractive onecolor array of red, green and blue lights, as presented
in Equation (1).8 By mixing a pair of CMY primaries,
secondary
colors
are
theoretically
created,
(cyan + magenta ¼ blue,
cyan + yellow ¼ green,
magenta + yellow ¼ red) and black is generated when
all CMY primaries are mixed:9
2 3 2 3 2 3
C
1
R
4M5 ¼ 415 4G5
ð1Þ8
Y
1
B
When separated into CMYK color layers, secondary
color regions are presented in lower gray values than
single primaries as two-color arrays are filtered and
placed together. In addition, CMY layers enclose with
implicit values to produce different tones of black when
the three colorants are combined. For example, the original image in Figure 2 is designed with cyan, magenta,
yellow, black, red, green and blue and shows the aforementioned features of CMYK morphology.
CMYK colors are ‘process-colors’ of which a range
of printable colors in varying percentages of ink with
levels of transparency are reproduced. Regions shared
by more than two colorants are designated second or
third color generation when they are overlapped and
mixed in subtractive processes.7 On the hand, as
opaque threads have no transparency and cannot be
blended, weave colors are produced by exhibiting
thread colors on the surface. When small particles of
yarn colors are observed, the color mixing effect is created. As a result, when the primary layers of the subtractive color scheme are directly applied to Jacquard
fabrication, inappropriate color reproduction resulted
due to the difference between pigment and optical color
mixing. In pigment mixing, although CMY colorants
are assigned to the creation of black, they are overlapped and produce rich tones of blacks; however, in
the optical thread mixture, the CMY colors of threads
solidify and coexist with black threads. Furthermore,
secondary colors are emulated by juxtaposing coupled
primary colored threads but, without transparency in
yarn material, it is limited to adopt the pigment mixing
principle in Jacquard color creation for secondary color
generation. In addition, as the regions with two-color
arrays in precarious color variation are considered
insufficient to produce projected colors in weaving
forms, color blocking lines distinctly appear on the borders where colors are changing to another. For that
Figure 1. Jacquard design and fabrication process for colored images.
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reason, the enhancement for reproducing weave colors
was proposed in partitioning the four primary layers
into C, M, Y, K, R, G and B color pattern to improve
the flaws of CMYK color scheme. By employing the
CMYK color system in which (1) secondary color areas
of the system appear in lower grayscales, (2) a
self-governed black layer exists and (3) an empty set
of all colors signifies white areas, it is possible to
apply region-based segmentation to subdivide a multicolored artwork into assigned color regions.
CMYs is combined, the relevant area is solely discovered. Yet, as they also contain values of black, the
subtraction process is applied lastly. The removal process is presented in Equation (3), where Rp , Gp and Bp
are the final color patterns of red, green and blue for
weave structure inputs, whereas Cg , Mg , Yg and Kg are
the layers obtained by computed separation. Figure 3
presents each pattern modification in detail:
2
3 2
Rp
Mg
4 Gp 5 ¼ 4 Cg
Bp
Cg
Region-based segmentaion to partition CMYK into
CMYKRGB color patterns
Region-based segmentation seeks to create regions directly by grouping together pixels that share common
features into areas or regions of uniformity. This
approach of the process is considered similar to image
regions having a common criterion for creation.10
Based on CMYK topographies, region-based segmentation was applied with mathematical morphology to
cluster independent C, M, Y, K, R, G and B patterns
and aims to supply an associated color of the yarn to
accurate areas to improve the insufficient CMYK color
scheme in optical color mixing of Jacquard color creation. Equation (2)11 is defined when two grayscale
layers are merged (1) to attain average grayscale
values between the upper and low layer to maintain a
constant outcome of the gray level throughout merging
processes, (2) to cluster individual patterns of red, green
and blue, (3) to eliminate supplemental color values
from each color pattern, (4) to produce continuous
tones of grays without truncation and (5) to subdivide
a whole image into integral regions. Where Ug is the
upper layer of the gray value, Lg is the lower layer, the
component grays range from zero to one:
f Ug , Lg ¼ 1 1 Ug 1 Lg
ð2Þ
\
\
\
3 2
1
Yg
Yg 5 4 1
1
Mg
3
Kg
Kg 5
Kg
ð3Þ
Patterning of cyan, magenta and yellow
As the filtered CMY layers have values of secondary
colors and black, the grayscale clarification gradually
proceeds. The grays of secondary values are first
removed while the black values are uninvolved during
the merging. The elimination is defined as Equation (4)
when CMY patterns with their own inherent values are
obtained where Cp , Mp and Yp are the final patterns for
structure inputs and Rp , Gp and Bp are the layers
attained by region-based modification of the original
CMY. Figure 4 shows the details of the CMY pattern
modification:
3 2
3 2
Cg
1
Cp
6M 7 6M 7 61
4 p5 ¼ 4 g54
2
Yp
Yg
1
2
3
1 Kg
6
7
4 1 Kg 5
1 Kg
3
1 Gp
7
6
Rp 7
5 4 1 Bp 5
Gg
1 Rp
Bp
3
2
ð4Þ
Structural weave design
Patterning of red, green and blue
Generation of varied lightness in weaving by shaded
weave structure design
The common sharing of a pair of CMY primaries designates the areas of red, green and blue. Once a pair of
Shaded weaves enabled reception of different degrees of
lightness and shades in a gradual manner and therefore
Figure 2. An example of a colored image and its primary layers achieved by auto-separation.
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Figure 3. The rendering process of red, green and blue color patterns.
Figure 4. The rendering process of cyan, magenta and yellow color patterns.
enabled presentation of created forms of motif in natural colors.12 Selection of a weave repeat was a decisive
factor. It was possible to develop plain and twill weaves
into shaded weaves, although satin and sateen structures were preferred for producing a maximum degree
of luster on the surface without distinguished weave
features. The length of thread floats was closely related
to the weave color saturation. Longer floats give better
saturation due to fabric firmness, with the ideal ranges
of weave repeats recommended to be within 40 40.5
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Figure 5. Creation of shaded weaves with different enhancing points.
The same weave repeat was given in both ends and
picks and began with at least one interlacing point in
each line of a structure. Sub-multiple numbers of a
weave repeat were accumulated for enhancing interlacements each time. Once a definite number of interweaving points were added, the transformed shape of a
shaded structure generated different levels of lightness
in weaving forms.13 Figure 5 shows examples of conceivable shaded weaves in a 16 16 form with sub-multiple numbers, and Table 1 shows details of each
circumstance, where E is the number of enhancing
interlacements each time and WR is the respective
weave repeat.
The enhancing points are found by regular step
movement in a vertical direction and this motion continued until the weave space reached the minimum
weaving point in each weave repeat. Although the
number of achievable weave varieties depended on the
selection of the sub-multiples, the series of shaded
weave designed with a small number of increases was
preferred. This is because the weave structures altered
gradually in-between, thereby making possible presentation of a smooth color deviation. In addition, the
attainable weave variety was estimated by the
Equation (5). As total interlacements of a weave
repeat (WR2) were first occupied by an initial stitching
point in each weave line (WR2 WR), the total number
of weave derivatives (T) was estimated based on the
given value of an enhancing number (E) as well as minimum stitching points {(WR E) 1}, which were subsequently left in an individual pick line through
interlacement accumulations:
T ¼ WR2 WR E fðWR EÞ 1g
ð5Þ
Compounding shaded weaves by the extra weft figuring method
The extra weft figuring method was designed to emulate
colors of an original image by juxtaposing a group of
filling yarns. The direction of enhancing interlacements
was important in distributing interweaving points
Table 1. Examples of 16 16 shaded weave design
16 16 shaded weaves
(a)
(b)
(c)
(d)
(e)
Enhancing points
Vertical step movement
Achievable shaded weave varieties
16
1
15
8
2
29
4
4
57
2
8
113
1
16
225
evenly throughout the forms of compounded shaded
weaves. The method of increasing interlacement transition was associated with maintaining structural balance
and also generating faithful color reproduction. These
directions were proposed in three different ways,
namely horizontal, vertical and diagonal, as shown in
Figure 6.
Different thread color effects were achieved by
employing direction of transitions. Horizontal transitions (a) were preferable for both thread color exhibition and structural balance. The vertical (b) and
diagonal (c) transitions, as shown in Figure 6, had
inconsistent connections in both fillings and ends, and
therefore short lengths of thread floats were generated.
In this manner, unsatisfied color exhibition of wefts and
irregular movements of warps were expected. In contrast, horizontal transition provided constant connections in filling floats. Moreover, the warp movement,
either to be shifted or lowered, was designed to be
bound in a group; thus, the ends moved regularly,
and longer floats of fillings appeared through the structure arrangement.5
The structures were received in the same starting
point and horizontal transition directions; the thread
floats of two combined structures were assembled in
patches. Figure 7 illustrates the two compound weave
structures.
When the first and second weaves took the same
horizontal direction and starting point (d), the compound structure exhibited interlacements in an accumulated way. The circumstances led to cramming of the
filling yarns with the resulted streaks broken when high
density was applied. In contrast, compound structure
(e) built with an opposite start and transition
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Figure 6. Three transitions for enhancing interlacement.
Figure 7. Comparison of two horizontal transitions in compound shaded structures.
distributes interlacements spatially. Besides, when the
two compounded structures received an identical step
movement, the warp motion might become disturbed.
As Figure 8 illustrates, if the different step movements
(g) were applied in a set, ends were regularly exhibited
between the two fillings. Yet, the weave (f), compounded with the same step number, obtained erratic
movements of ends.
Therefore, in reflection of the optimal condition,
that is, starting point, step movement and transition
direction in compound weave structures, two groups
of shaded weave structures were designed for weave
color reproduction. Each series of weave groups was
alternately provided in structure layouts to achieve an
even color appearance of filling yarns.
Experiment and results
In this study, the design image, previously presented in
color pattern segmentation, was used to prove the
improvement of weave color reproduction in an application and then experimented with a multi-colored
image to broaden design concepts for Jacquard fabrication. In order to make a comparative analysis, physical samples were produced for the CMYK and
CMYKRGB color schemes. Based on the gray values
of the individual weave patterns, the two sets of shaded
structures were alternately applied. Table 2 shows the
technical specifications of the experiment.
The same 16 16 shaded weave structures were used
in the sample production of both color schemes.
Differences were found in the composition of weave
patterns and the assortment of filling yarns. Figure 9
shows the first image (A1) of the color reproduction
and the limitations of having the computed CMYK
color layers (A2) as a weave pattern for multiple
weave color creation. The presence of unnecessary C,
M and Y floats was unavoidable in the black regions, as
the subtractive color mixing principle (i.e.,
[C] + [M] + [Y] ¼ [K]) was applied to non-blended
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Figure 8. Step movements in compound shaded structures.
Table 2. Experiment of weaving specification
Weaving parameters
Composition
Material
Thread color
Yarn count
4 color filling density
7 color filling density
Jacquard machine
Pattern/structure Design
Pattern repeat (A1)
Pattern repeat (B1)
Weave repeat
Shaded weave verities
Software applied
Warp
Weft
100% polyester
Off-white
100 denier
120 threads/inch
120 threads/inch
Stäubli JC6
100% polyester
Cyan/magenta/yellow/black Red/green/blue
50 denier
66 threads/inch
56 threads/inch
25.4 cm (width)
25.4 cm (width)
16 16
57
Photoshop CS/Arhne CAD
23.75 cm (height)
45.36 cm (height)
yarn material. In addition, the absence of red, green
and blue was verified as there was no transparency
and light transmission in pre-dyed colorant threads.
The proficiency of continuous tones was crucial, but
the CMYK scheme was insufficient to achieve the
finest color display on the surface. Conversely, in the
case of the CMYKRGB color production (A3), the two
sets of primary colors were placed in the regions where
they were associated and the unwanted CMY thread
floats in the black areas were minimized. The natural
gradation of color generation was achieved according
to the original image and the fillings were occupied in
conformity with the color patterns. The improvement
achieved by color pattern adaptation was prominent
compared with the CMYK color scheme (A2).
Based on the results, a further experiment was conducted to inspect the practicality of the invention on
various designs. As a spectrum had two primary sets
and presented the colors in progressive chromatic variations, an image (B1) was designed for colors difficult
for red, green and blue ranges to reproduce. Figure 10
illustrates the result of the experiments. Compared with
(B3), the CMYK system (B2) was found to be deficient
to reproduce the inherence of the secondary colors by
superimposing coupled non-transparent primary colors
of yarns. Yet, (B3) was closer to the original image. In
subtractive mixing, red, green and blue color were realized by pairwise primary color mixing with levels of
transparency
in
inks
(i.e.,
[C] + [M] ¼ [B],
[M] + [Y] ¼ [R] and [C] + [Y] ¼ [G]). However, in the
optical thread color mixture, since the color mixing
effect was created based on the light reflection of the
cloth surface, it was difficult to simulate the color
ranges that were realized through light transmission
in a material substance. Therefore, associated precolored yarns were supplied and fulfilled the defined
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Figure 9. Fabrication of CMYK (A2) and CMYKRGB (A3) in A1 design.
Figure 10. Spectrum of color reproductions in CMYKRGB (B2) and CMYK (B3).
regions with a proper amount of thread color exhibition and the improvement of weave color reproduction
was attempted and applied.
crucial reference for the fabrication of multi-colored
images.
Funding
Conclusion
Juxtaposing non-transparent threads adopted a different approach to color scheming in terms of light and
pigment mixing. For optical thread color mixing,
shaded weave structures were employed to create natural colors and color patterns were designed to place C,
M, Y, K, R, G and B colors in layers to optimize weave
color reproduction. Color patterns and weave structures were required to align with each other for
mutual correspondence. A variety of concepts have
been proposed for Jacquard fabrication, and applications vary from one situation to another. Yet as this
study aimed to improve designs composed of two
groups of crucial primaries in varied degrees of lightness, the proposed application serves as a piece of
This work was supported by the General Research Fund of
the University Grants Council and The Hong Kong
Polytechnic University.
References
1. Robinson ATC and Marks R. Woven cloth construction.
Textile Institute: Manchester, 1973, p.24.
2. Watson W and Grosicki Z. Watson’s advanced textile
design: compound woven structures, 4th edn. NewnesButterworths: London/Boston: MA, 1977, pp.13–25.
3. Zhou J. Research and creation of printing-like effect digital Jacquard fabric. Adv Mater Res 2011; 295–297:
2568–2571.
4. Ng MCF and Zhou J. Full-colour compound structure for
digital jacquard fabric design. J Textil Inst 2010; 101:
52–57.
Downloaded from trj.sagepub.com at PENNSYLVANIA STATE UNIV on May 11, 2016
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(TRJ)
[1–9]
[PREPRINTER stage]
Ng et al.
9
5. Ng MCF and Zhou J. Innovative layered-combination
mode for digital jacquard fabric design. Textil Res J
2009; 79: 737–743.
6. Zelanski P and Fisher MP. Colour, 3rd edn. Herbert Press:
New York, 1999, pp.77–78.
7. Kendra E and Against the Clock (Firm). Color companion
for the digital artist. Pearson/Prentice Hall, NJ: Upper
Saddle River, 2004, pp.39–41.
8. Lau DL and Arce GR. Modern digital halftoning, 2nd ed.
CRC Press: FL: Boca Raton, 2008, p.337.
9. Berns RS, Billmeyer FW and Saltzman M. Billmeyer and
Saltzman’s principles of color technology, 3rd edn. Wiley:
New York, 2000, pp.151–172.
10. Awcock GJ and Thomas R. Applied image processing.
Macmillian, Basingstoke, 1995, p.127.
11. Hamburg S and Valley S. Blending colours in the presence
of transparency. Patent 6,421,460 B1, USA, 2002.
12. Watson W and Grosicki Z. Watson’s textile design and
colour: elementary weaves and figured fabrics, 7th ed.
Newnes-Butterworths: London, 1975, pp.221–225.
13. Zhou J, Tang T and Hu D. Grey simulative effect digital
Jacquard fabric design with full-colour compound structure. Adv Mater Res 2011; 332–334: 663–666.
Downloaded from trj.sagepub.com at PENNSYLVANIA STATE UNIV on May 11, 2016