Shadow knitting, or illusion knitting, is a process of knitting such that the finished piece has a hidden image only viewable from an angle. The effect is created by alternating rows of two colored yarns so that the raised stitches from one row block out the flat stitches of another row. The finished work looks like a simple striped pattern from the front, but when viewed from an angle, the "hidden" image appears.
The first image is a piano keyboard pattern that I knitted. The second and third are a simple block pattern for this instructable viewed straight on and then at an angle.
Step 1: Gathering Materials and Creating a pattern
This process relies on raised stitches, so worsted or sweater weight yarns work best. Homespun yarns or yarns that have irregular shapes do not work as well.
You will need two contrasting colors, usually a light and a dark work best.
To create the pattern you will need graph paper or a spreadsheet program like Microsoft Excel. For the sake of this instruction set, I have created a simple block pattern that is 20 stitches wide and 6 stitches high, repeated indefinitely.
After the basic pattern has been created choose which of your two yarn colors you will start with. This will be your "background color" The other color will be the "pattern color". We'll call them "Color 1" and "Color 2". For this set Color 1 will be white and Color 2 will be blue.
The trick to shadow knitting is in reading the pattern. Each single row in the pattern represents 4 knitted rows.
Row 1a - Color 1 - Knit across
Row 1b - Color 1 - Knit and Purl in pattern
Row 1c - Color 2 - Knit Across
Row 1d - Color 2 - Knit and Purl in Pattern