Curvature Blindness Illusion
Designer and Artist: Irena Swanson
Materials and Methods: Machine quilted and bound cotton fabric and batting
Year of Creation: 2022
The heights of all fence pieces are identical, and the heights of all adjacent yellow pieces between the fences are identical, yet half of the fences appear curved and half appear jagged. The illusion results from the small amplitude in the discretized sine curve and the dark-light values of the pieces: medium for the background, high contrast for the fences. More about the illusion and the importance of amplitude and value can be found in the paper by illusion designer and psychologist Kohshe Takahashi's "Curvature Blindness Illusion" (also here).
The total number of pieces in the quilt top is 992, created from 32 strips cut selvedge to selvedge. Traditional methods would have required 991 seams, but the method that I call tube piecing allowed me to use only 95 seams. The top and bottom edges used to be together in a wide tube sewn from 62 narrow tubes, until a cut separated them into the visible rectangle. Those 62 narrow tubes were cut at width 1.25 inches from three different primary wide tubes: one such tube was made from only yellow and black strips, one from only yellow and white strips, and the third using all three colors. (On the first two strip sets I first performed what I call double-the-width-and-halve-the-height maneuver to get three primary wide tubes of the same circumference.) In my quilt piecing, I try to minimize leftovers and the number of seams, for which tube piecing is ideal.