Marcy Petrini 

September, 2025 

In the June 2025 blog I described the opponent color wheel, as shown below again:

This results from the way our visual system perceives colors:

Red ↔ Green Spectrum

Blue ↔ Yellow Spectrum

Light ↔ Dark Continuum

In the July 2025 blog, I showed a plain weave fabric with the two opponent colors, red and green, which became dull from the optical blending.

However, opponent colors do not always look dull toogether. Our visual system responds to the circumstances in which it sees colors.

First, our brain detects a shape, then it fills it with color.

If the brain can’t detect the contour of the shape – the individual threads or motifs – the colors will blend. In July 2025 we saw that blending can result in pleasing combinations or in dull fabrics, depending on the colors.

If the contour of the shape can be detected, then the brain looks at the colors while our eyes jerk from spot to spot, called a saccade. If the colors happen to be opponent, for example red and green the fabric will be shimmering.

Compare the next two samples: the first is the one from the July 2025 blog: red warp with green weft in plain weave, resulting in a rather dull optical blending.

The second sample is also a red warp and a green weft but woven with a twill. There are enough treads together to provide a good saccade: the fabric shimmers.

An even more shimmering fabric results from the sample below which was woven with a red ground warp, a green supplementary warp and a red weft, same as the warp.

The large areas of green on top of the red makes the blocks seem to float.

In contrast, below is a sample using the same red warp and green supplementary warp; the weft, however, is green, the same as the supplementary wasp.

There are a two visual effects here. One is the optical blending of the red and green plain weave, resulting in a dull fabric as we saw in the first example.

However, it is hard to believe that the supplementary warp in the sample below is the same as that of the sample above! The contour detection between the optical blended background and the green blocks is blunted, so the saccade doesn’t result in a vibrant outcome. The block edges are less clear and the green is not shimmering.

Understanding these opponent colors allows us to manipulate our yarns for our projects. A holiday runner in red and green? Try a bold twill or blocks, but no plain weave in red and green.

Happy weaving!

Marcy