Tribar
The tribar was designed in 1934 by the Swedish Artist Oscar Reutersvärd.
The mathematician Roger Penrose tried to create impossible geometric shapes after he visited an exhibition of M.C. Esher. He created the same pattern and published it with his father in 1958 in the British Journal of Psychology. So it is also known as the Penrose Triangle.
When you look onto an illusion knitting the proportions are distorted a little bit. This pattern is longer than the original to minimize this effect.
Galloromanic knots
This illusion is inspired from a mosaic of the galloromanic Villa Seviac near Montreal.
I’ve drawn these knots and others as patchwork patterns because some of these mosaics from the 4th century look like traditional quilt blocks. As I was searching for an example how to try an illusion quilt of my own I decided to use it, too. There are several ways to put it onto a wall. Here I decided to put it into a frame like a window.
The instructions in English and German language will be available at Ravelry soon.