Anyone involved in graphics and design is fond of optical illusions, as we need to understand tricks of visual perception, in order to play tricks on our customers.

Count the colors in the following picture:

You may think there are four, you would be wrong, there are only three.

The green and blue, no matter how hard it is to beleive, are the same color. Try loading the picture in ArahPaint, and you will see that it has only three. To get the picture, press right mouse button and choose "Save image as...".

Akiyoshi Kitaoka, the designer of this optical illusion used "simultaneous contrast", that is an illusion where perceived color changes based on surrounding colors. In this case, violet and orange surrounding colors force the color shift.

How is this relevant to textile design? We are always trying to do more with less, so making an illusion of four colors, when we only have three, can be useful.

First let's make a simple design with some stripes, since we don't want the customer to feel dizzy because of the spiral.


We start with a simple construction of one warp and two wefts


We use similar colors as the one in initial color illusion.
Next we load the picture in jacqaurd conversion, set it to "Extra wefts", and "System" 2.


We use double satin 8 to alternate between two wefts, and warp satin 8 for warp effect of third color.

In fabric simulation, it looks like this.

If you can't see the illusion well, we can zoom out the simulation, and you will see the "different" green and blue color.


We have made a fabric, whose colors change depending on viewing distance!
We can also use a different, more tight weave construction, without extra wefts.


We use double alternating twill for first two colors, and twill or satin 8 for third color.
We have also rotated the image, and this is the simulatoin.

With a little extra effort, we could also do this on a dobby loom, by reducing image complexity, or choosing a smaller set of weaves,
like twill 1/3.