Illusion knitting

Illusion knitting or shadow knitting is a form of textile art, in which the knitting is viewed as simply narrow stripes from one angle, and as an image when viewed from another angle. Illusion knitting has been recognised as an art form since 2010, largely due to the advances made by Steve Plummer who has created several large and detailed pieces. Similar effects occur in Tunisian crochet.

Illusion knitting uses two colours of yarn and is worked in stripes of two rows in each colour. Illusion knitting is based on the flat smooth and the raised garter stitch. It is this combination of textures which allows the image to be seen only from the proper angle.

Traditionally, charts for illusion knitting use four rows of knitting symbols to represent the stitches which the designer wishes to be seen. This makes the charts elongated and difficult to use for anything other than simple blocks of colour. These four rows make up two pairs where, in most cases, one pair is considered the opposite of the other. Where one pair has two rows of knit stitches, the other image pair has both knit and purl stitches.

As in mosaic knitting, the knitter alternates between two colors. Colors with good contrast are preferred but are not required. The knitter knits two rows of color A, then two rows of color B, and repeats this throughout the body of the work. Only knit or purl stitches are used.

Each row in the pattern, shown in the thumbnail to the right, represents four rows of knit or purl stitches, and each column represents one stitch. To follow this pattern, a knitter would use black and white: white being the background color (BC), and black being the master color (MC).

The visual effect of shadow knitting is due to the different height of the knit stitches on the wrong side rows. A knit stitch is flat, while a purl stitch is raised. Therefore, one can change which color (dark or light) stands out by changing from knit to purl. So the basic idea is to create a pattern in knit stitches in the colors one wants and purl stitches in the background color. When looking straight at the knitted piece, the stitches look approximately the same, but from an angle, only the raised purl stitches are visible.

There are no constraints on the position of the purl/knit stitches, so a nearly infinite variety of patterns can be made. The pattern will not be apparent from every direction of viewing, since one ridge may "overshadow" another. Knitters often enjoy watching when the picture created becomes visible. The stark contrast of alternating light and dark stripes is also visually interesting.

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Wikipedia