Traditional Dyeing and Weaving: Karamiori
Ro is a weave which employs the sha structure with the addition of areas of flat and/or twill weaves. A simple version of this is shown in the diagram to the left in which the pairing of the warp threads remain the same, but additional warp threads are added in a flat weave to form selvage to selvage banding.
To the lower left is an example of an artist manipulating the warp threads by hand, one pick at a time, to create the twist. There is another method used for more complicated imagery: a “therapy-thread” (my term–it’s really called a doup thread) is lightly knotted to a given warp thread. It is then manipulated over and under adjacent warp threads following the path of the desired twist. When pulled upright it will force a distortion in the lay of the warps saving quite a bit of hand picking effort. Hundreds of these may be prepared to pull up in unison allowing for some of the patterns you see below, and helping to avoiding years of intensive one-to-one therapy with a mental health-care professional.
Nara Period Clamp Resist Dyeing on RA 茶地鹿花卉文夾纈羅
Karamiori (絡織り搦み織り), the tangling of threads to create nets and gauze-like fabrics, is a very old and highly respected form of textile production. Believed to have first been introduced to Japan from the mainland during the Nara Period (710-794) for use in temples and by the ruling class.
Basic Ro Structure. Notice the addition of the weft threads forming a flat-weave band.
Today these weaves are enjoyed by a broad range of everyday people in both traditional dress and cutting edge fashion.
Doup Thread Used to Simplify
Warp Manipulation
The verb karamu means to entwine, entangle. (Curiously, it also means to pick a quarrel. Hmmm, this may also say something about the exacting nature of this technique.) And so in Japan this category includes all loom techniques that make use of intertwining threads to create the structure of the weave.
Elegantly simple karamiori haori for a summer's day. The dark color of the weave in contrast to the lighter-colored kimono beneath helps the wearer appear cool and refreshed.
Karamiori woven gown of pure gold. GINZA TANAKA
Many methods that fall under this Japanese category are called leno weaves. The basic definition of a leno weave in English is as follows (from A weave structure in which paired warp yarns are intertwined in a series of figure eights and filling yarn is passed through each of the interstices so formed, producing a firm, open mesh.
Seductively cool and iridescent ro, combining a twill weave with the basic sha structure.
Ro is certainly not limited to banding alone. By combining the flat and twill weaves with the leno structure, and varying their placement within the yardage, very complex designs may be achieved.
There is a wonderfully clear video clip on You-Tube by Patty Anne showing how a leno weave is created:
With the basic background a sha structure, portions of the weft threads have been diverted to flat weave, creating a pattern of cool droplets of water on a stark black silk.
With ra, we have ventured into new territory–while maintaining the concept of the twisted threads, we are no longer in the realm of monogamous unions. Pairs are now freed to meander and recombine forming highly intricate webs of relationships. Patterning in ro is dependent upon the emotional support of outsider (flat/twill) weaves, however  ra is entirely contained in its own journey of meandering warps. Only the barest minimum of wefts are employed to keep the society of threads stable.
Manipulating the Warp Threads to Create Twists
It sure looks like a lot of work, doesn’t it? So why bother?
This is really the only way to achieve a light, airy weave that won’t bruise easily. It allows light and air to pass through the weave freely while maintaining its structure. If a simple in-and-out flat weave were woven very loosely to achieve this same affect, the threads would have a tendency to shift from side to side (bruise) if rubbed, disturbing the beauty of the weave.
I've color-coded the warp threads in this diagram to make it easier for you to follow their complex relationships. As wild as the intercourse may seem at first glance, the basic weave structure of in-and-out, over-and-under, is followed at all times.
In the diagram above you can see two basic cliques at work, the bolder social network to the left and the slightly more timid grouping to the right. Now take a look at the image of the ra on the loom, below. Notice how integrated these slight variations become when used as part of a grander scheme.
Bruised Satin-weave Chiffon. I had only to firmly rub the fabric between my thumb and index finger to cause the threads to shift and create a permanent bruise in the weave.
The Japanese divide karaori into three basic styles based on structure: sha (), ro (), and ra (). Please keep in mind that the boundaries of each may vary depending on who is using the term, and whether or not they are addressing the technique or the mood of the weave.
Sha is the simplest of the three and basically has no discernible pattern. Pairs of warp threads are mated to twist back and forth around one another so that in the end they appear to be a single thread. (This matches the definition given above.) The even
Waxed Cotton Sha. Notice how the twisted warp threads create a vise-like grip on the weft yarn.
Ra Weave on Loom
gaps formed between the pairs of warp threads and by the spaces between the solo-weft threads is what allows for the open, even, gossamer quality of the weave.
In the case of ra, the definition given at the top of the page does not apply. As you can see in the diagram, the interlocking threads are not limited to simple pairs. The definitions found in Japanese textile dictionaries don’t refer to a specific structure so much as descriptions of how it appears, likening it to bird nets and open-weave basket structures.
Simple Sha Weave Structure. The figure eight formed in the twist helps to keep the threads from shifting.
The Japanese and Chinese were not the only ones cavorting in warped acrobatics during these ancient times. Across the world in the high Andes Mountains, equally stunning masterpieces were being fabricated.
Sample of Ancient Andean Ra