Showing posts with label optical mixing. Show all posts
Showing posts with label optical mixing. Show all posts

Monday, February 24, 2025

Some Notes from My New Lecture, 'You Can't Judge a Warp by Its Color'

 



When I teach workshops on Echo and Jin using a 4-color parallel threading, weavers will often say to me, "I don't like the colors in my warp." I jokingly answer, "You can't judge a warp by its color." I do mean this seriously, because your weft makes a big difference (owing to a principle of optical mixing known as "simultaneous contrast," which I'll discuss later), as does your pattern, as do the rods and cones in your eyes. 

I've created a new lecture with just this title, and in it I try to unwrap some of the mysteries of color in weaving, looking at color chords, color blending, our own rods and cones (which number in the millions) and how to develop a greater understanding of what colors to use in your own work. 

In this blog post, I'm looking at just one of the concepts in my talk -- but one that is of primary importance: the concept of "simultaneous contrast," a term seldom used today, but a concept very useful to weavers.

Above, in the first photo, you see my warp colors in 10/2 pearl cotton, based on a rectangle taken from Johannes Itten's publication, "The Color Star." If you're lucky enough to have one, it's enormously helpful as it presents 8 templates that can be rotated around his 12-point color star, providing all sorts of options for choosing hues and values for what he calls "color chords" that are harmonious and satisfying to the eye.

My warp colors were turquoise, bright green (not quite chartreuse), orange, and wine. All quite saturated, with the wine color being the darkest in value.

In the second photo, you see a 16-shaft design I call "Tesselations," which uses a 20/2 pearl cotton weft in olive green. To my eye, the turquoise now appears to be a lighter blue, the orange becomes more of a rust color, the green is now definitely chartreuse, and the wine color is now more of a purple.

What happened? Simply put, simultaneous contrast. 



Above: Two images from Josef Albers's classic book, The Interaction of Color, showing (in the first image) how the rust-colored square against a teal background becomes brown against a copper-colored background and (in the second example) how a raspberry-colored trapezoid appears light and pinker against a black background (at top) and appears darker and more raisin-colored against a dark adobe background.

Simultaneous contrast was discovered by French chemist M.E. Chevreul in 1839, after he was hired by the Gobelins tapestry studio to determine why their black dyes were not consistent. He analyzed their dyes and found that, in fact, they WERE consistent -- and he went a step further, developing what he called the"Law of the Simultaneous Contrast of Colours." 

Simply put, "this color placed next to that one is modified as follows," he wrote in 1854. He added in a review in 1855: "the purport of this law, is to point out the singular fact, that when two coloured objects, such for example as a red and a green ribbon, are place side by side, or so near each other as to be seen together, the quality and intensity of their respective colours do not appear the same as when each is looked at separately. Thus, the same red ribbon will have a different tint if seen side by side with a green, with a yellow, and with a blue ribbon, and these colours will in their turn be modified to the eye, by their juxtaposition with red. This is the Simultaneous Contrast of Color."

I like to put it simpler, by saying that colors bend toward each other. And this concept is particularly important in weaving, because of the pixelated nature of warp and weft appearing over and under the cloth.

Here's an example, a double-weave sample on 8 shafts using an Echo design. What colors do you see in this warp? If I were to guess, I would say mint green and magenta.


Wrong! The warp colors are cherry red and leaf green (shown below), which happen to be complements.


The colors in the warp change considerably because the weft, if you can detect it, is purple. The purple makes both the red and the green appear bluer.


To dig deeper into this concept, let's try the familiar trick of staring at a colored dot and then staring at a white background. First, focus your eyes for about 10 seconds on the dot in the center of the yellow circle. Then focus on the dot in the center of the white rectangle.


You see a hazy purple circle, right? Purple is the complement of yellow. This is central to the concept of simultaneous contrast. The cones in your retina become fatigued in staring at the yellow, leading to a temporary imbalance in which the opposing color (its complement) appears when you look away.

What does this afterimage effect have to do with color blending in weaving? Quoting from http://onlineartlessons.com: "The law of simultaneous contrast describes the phenomenon where two colors juxtaposed... will influence each other, causing each color to take on the hue of the complementary color of its... partner." 

I confess I have yet to figure out exactly how this works when I look at weaving samples or drawdowns. I don't see colors taking on the complement of their partner but rather I see them taking on an element of their partner, as in the example below. (Comments, thoughts, insights appreciated.)


In this partial drawdown of an Echo pattern I designed using Fiberworks, there appear to be two shades of green in the cloth. Yet there is only one shade of green in the weaving: a medium grass green in the weft. The warp is khaki and purple.

Why do the greens shift in the drawdown? Again, because of simultaneous contrast. Remember that weaving is, effectively, a pixelated method of creating patterns. So when a "pixel" of green weft is close to a "pixel" of purple warp, the green appears to be more like a teal blue. (I attribute this to the green taking on the blue shade in the purple.) And when the green weft is next to the khaki warp, it appears to be brighter green, taking on the yellow in the khaki warp. 

Weavers can use these effects to optimize color-blending in their work, particularly with parallel-threaded patterns. As in the drawdown above, three colors of yarn in the design produce four colors in the cloth, adding interest and richness to the overall piece.

But back to M.E. Chevreul at the Gobelins studio. As he began writing about his observations on how colors affect each other and how complements and simultaneous contrast can produce shifts in colors that add energy to a work of art, the Impressionists took note.


Above, Monet's "Impression, Sunrise" from 1874, with its complements of orange and blue, is credited with inspiring the name of the Impressionist movement. 

It took a chemist, analyzing color scientifically, to give artists a greater understanding of how colors can work to add energy, to soothe, to excite, and to dramatize their vision.


Van Gogh, Café Terrace at Night, 1888

Thanks for reading!



Wednesday, August 18, 2021

Shaft Envy, Begone!

 





You don't need 32 shafts to weave beautiful fabric! I'm on a mission to prove this as I work on designs for a new workshop, "Echo on the Double: 4-Color Double Weave for 4 to 32 shafts." The workshop will include 5 to 6 variations in tieups and treadlings for each pattern, all in double weave, for any kind of treadle loom from 4 to 32 shafts. 

Pictured above, in the first 2 photos: Blooming Leaf design, Echo threading on 4 shafts in 4-color double weave, front and back. Second 2 photos: Falling Stars design, Echo threading on 8 shafts in 4-color double weave, front and back. The warp colors for all 4 designs are lime green and azalea.

Double weave on Echo threadings is endlessly fascinating because of the variety of patterns and color combinations that you can achieve. When you start with 2 colors in the warp (for a 2-end parallel threading) and then add 2 colors in the weft (one for the bottom layer and one for the top layer), you're working with 4 colors in all, which keeps color folks like me happy. And sometimes you'll wind up with the appearance of more than 4 colors, as in these samples below.


I used a sky blue and a beige linen as wefts, with lime green and azalea as warp colors. Look closely and you'll see a bit of the blue weft highlighting the pattern on this 8-shaft design.


The back looks quite different. Here, the sky-blue weft alters the lime-green warp, making it appear more like turquoise. It also alters the azalea warp, making it look more lilac. 
The color differences are more pronounced when you see this piece "in the flesh."

This color-shift effect is called optical mixing. (I also define it as "simultaneous contrast" because the colors of warp and weft appear different depending on which colors they lie next to). Echo as double weave allows you to exploit and play with this effect, regardless of the number of shafts on your loom.


Above, Blooming Leaf design on four shafts. The warp colors are the same as the 8-shaft design in the photos preceding this. The weft yarn for this layer is sky blue, which again softens the lime green, making it appear turquoise, and shifts the azalea to more of a lavender hue.


For the bottom layer, I used a burnt-orange weft color, which pretty much overwhelms the lime-green warp, turning it into a pale gold/bronze, while the azalea warp becomes more of a coral/orange. I like the bold color differences between the front and the back of the fabric.

There are so many other possibilities as well. For instance, I will be weaving some samples using overtwisted yarns as wefts, which cause the fabric to wrinkle and pleat in interesting ways. The key here is that the design has to include "pockets," as Marian Stubenitsky refers to them in her book, Echo and Iris. This is where the two double-weave layers are weaving separately, which doesn't always happen with double weave on Echo threadings. Often, you're weaving "integrated double weave," where the two layers are interlaced.

And then I would like very much to try weaving with copper as one of the warps and as one of the wefts, but that will have to wait until another time. First, I need to weave up a complete sample set for this workshop. Note: I've found that, as confident as I can be when I look at a design in Fiberworks, I still need to weave it up to see how it plays out. There are often surprises!

Then again, the surprises can lead to discoveries, don't you agree? And discovery is one of the reasons we love this craft.

Thanks for reading!


Falling Stars pattern on 8 shafts, Echo threading, double-weave tieup and treadling, 
with overtwisted yarn as one of the wefts.