Kogin is a uniquely Japanese needlework technique that was born of a practical desire for warmth, and the need to strengthen a fabric used in everyday life. Kogin is recognized by its characteristic blue and white geometric designs, which are embroidered with thick threads on a base fabric. The origins of this technique can be traced to the peasants in the Tsugaru Peninsula at the northwestern tip of Honshu - Japan's main island – in the 1600's. The characteristic blue and white designs were given names for things common to everyday life (soybean, cat's eye, running waters, etc.) Naming the patterns for items surrounding a stitcher helped to recall the patterns from memory, since formal graphs or charts had yet to be developed. Eventually, over three hundred patterns grew from the diamond shape, with certain designs associated with specific geographic areas.
Three distinct terms were used to refer this form of needlework during its history. The first term - Sashiko - is simply translated as "to stitch." Those designs stitched over an even number of threads are called Nambu Hishi Zashi ("diamond-shaped stitchery".) In contrast, the designs stitched over an odd number of threads were identified as Kogin. The first written reference to this form of needlework appeared in 1788 in "The Illustrated Book of the Life of the People of Aomori." In this book both techniques (odd and even-counts) were grouped together as Kogin, the term by which we know this form of needlework today. Generally, a design is made up of patterns using only an odd or even number of threads. The two counts are not mixed with each other, because the shape and angle of the diamond (or square) thus formed varies between the two. There are four major types of Kogin designs: 1. An all-over pattern, in which the design is worked from edge to edge; 2. A straight band, which may be vertical or horizontal; 3. A diagonal band of stitching and 4. A Freestanding design framed by larger portions of unstitched fabric. In contrast to Sashiko (a form of needlework known to quilters), the designs are based on a counted-thread approach and are stitched in a row-by-row manner across the entire width (or length) of the fabric.
Traditional Kogin designs were used on wearable clothing, and are easy to recognize by white threads stitched on a dark blue background. In historic examples of this form of stitching, both the threads and fabrics selected would be able to withstand hard use and frequent laundering. During the period of Kogin's rediscovery in Japan, however, color was introduced (both in the fabric and in the thread.) This form of stitching began to be seen on a wider variety of consumer articles - bags, purses, belts, etc. Kogin projects are functional items and the combination of threads and fabric selected should reflect this tradition