Crochet is a process of creating fabric from yarn or thread using a crochet hook. The word is derived from the Middle French word croc or croche, meaning hook. Crocheting, similar to knitting, consists of pulling loops of yarn through other loops. Crochet differs from knitting in that only one loop is active at one time (the sole exception being Tunisian crochet), and that a crochet hook is used instead of knitting needles.
Other writers point out that woven, knit and knotted textiles survive from very early periods, but that there are no surviving samples of crocheted fabric in any ethnological collection, or archeological source prior to 1800. These writers point to the tambour hooks used in tambour embroidery in France in the eighteenth century, and contend that the hooking of loops through fine fabric in tambour work evolved into "crochet in the air." Most samples of early work claimed to be crochet turn out to actually be samples of nålebinding. Donna Kooler identifies a problem with the tambour hypothesis: period tambour hooks that survive in modern collections cannot produce crochet because the integral wing nut necessary for tambour work interferes with attempts at crochet. Kooler proposes that early industrialization is key to the development of crochet. Machine spun cotton thread became widely available and inexpensive in Europe and North America after the invention of the cotton gin and the spinning jenny, displacing hand spun linen for many uses. Crochet technique consumes more thread than comparable textile production methods and cotton is well suited to crochet.
Beginning in the 1800s in Britain, America and France, crochet began to be used as a less costly substitute for other forms of lace. The price of manufactured cotton thread was dropping, and even though crocheted laces took up more thread than woven bobbin laces, the crocheted laces were faster to make and easier to teach. It's believed that some lace manufacturers paid so little that their workers resorted to prostitution.
During the Great Irish Famine (1845-1849) , Ursuline nuns taught local women and children to thread crochet. It was shipped all across Europe and America and purchased for its beauty and also for the charitable help it provided for the Irish population.
Hooks ranged from primitive bent needles in a cork handle, used by poor Irish lace workers, to expensively crafted silver, brass, steel, ivory and bone hooks set into a variety of handles, some of which were better designed to show off a lady's hands than they were to work with thread. By the early 1840s, instructions for crochet were being published in England, particularly by Eleanor Riego de la Branchardiere and Frances Lambert. These early patterns called for cotton and linen thread for lace, and wool yarn for clothing, often in vivid color combinations.
Around the world, crochet became a thriving cottage industry, particularly in Ireland and northern France, supporting communities whose traditional livelihoods had been damaged by wars, changes in farming and land use, and crop failures. Women and sometimes even children would stay at home and create things such as clothes and blankets to make money. The finished items were purchased mainly by the emerging middle class. The introduction of crochet as an imitation of a status symbol, rather than a unique craft in its own right, had stigmatized the practice as common. Those who could afford lace made by older and more expensive methods disdained crochet as a cheap copy. This impression was partially mitigated by Queen Victoria, who conspicuously purchased Irish-made crochet lace and even learned to crochet herself. Irish crochet lace was further promoted by Mlle. Riego de la Branchardiere around 1842 who published patterns and instructions for reproducing bobbin lace and needle lace via crochet, along with many publications for making crocheted clothing from wool yarns. The patterns available as early as the 1840s were varied and complex.
Fashions in crochet changed with the end of the Victorian era in the 1890s. Crocheted laces in the new Edwardian era, peaking between 1910 and 1920, became even more elaborate in texture and complicated stitching.
The strong Victorian colors disappeared, though, and new publications called for white or pale threads, except for fancy purses, which were often crocheted of brightly colored silk and elaborately beaded. After World War I, far fewer crochet patterns were published, and most of them were simplified versions of the early 20th century patterns. After World War II, from the late 40's until the early 60's, there was a resurgence in interest in home crafts, particularly in the United States, with many new and imaginative crochet designs published for colorful doilies, potholders, and other home items, along with updates of earlier publications. These patterns called for thicker threads and yarns than in earlier patterns and included wonderful variegated colors. The craft remained primarily a homemaker's art until the late 1960s and early 1970s, when the new generation picked up on crochet and popularized granny squares, a motif worked in the round and incorporating bright colors. Although crochet underwent a subsequent decline in popularity, the early 21st century has seen a revival of interest in handcrafts and DIY, as well as great strides in improvement of the quality and varieties of yarn. There are many more new pattern books with modern patterns being printed, and most yarn stores now offer crochet lessons in addition to the traditional knitting lessons. Filet crochet, Tunisian crochet, broomstick lace, hairpin lace, cro-hooking, and Irish crochet are all variants of the basic crochet method.
Crochet patterns have an underlying mathematical structure and have been used to illustrate shapes in hyperbolic geometry that are difficult to reproduce using other media or are difficult to understand when viewed two-dimensionally.
Crochet hooks come in many sizes.
Steel crochet hooks range from 3.5 to 0.4 millimeters in the size of the hook, or from 00 to 16 in American sizing. These hooks are used for fine crochet work.
Aluminum or plastic crochet hooks are available from 2.5 to 19 millimeters in hook size, or from B to S in American sizing.
There are also many artisan-made hooks, most of hand-turned wood, sometimes decorated with semi-precious stones or beads.
Crochet hooks used for Tunisian crochet are elongated and have a stopper at the end of the handle, while double-ended crochet hooks have a hook on both ends of the handle. There is also a double hooked apparatus called a Cro-hook that has become popular.
and so on.
To help counter confusion when reading patterns, a diagramming system using a standard international notation has come into use (illustration, right).
Another terminological difference is known as tension (UK) and gauge (U.S.). Individual crocheters work yarn with a loose or a tight hold and, if unmeasured, these differences can lead to significant size changes in finished garments that have the same number of stitches. In order to control for this inconsistency, printed crochet instructions include a standard for the number of stitches across a standard swatch of fabric. An individual crocheter begins work by producing a test swatch and compensating for any discrepancy by changing to a smaller or larger hook. North Americans call this gauge, referring to the end result of these adjustments; British crocheters speak of tension, referring to the crafter's grip on the yarn while producing stitches.
One of the more obvious differences is that crochet uses one hook while most knitting uses two needles. This is because in crochet, the artisan usually has only one live stitch on the hook, while a knitter keeps an entire row of stitches active simultaneously. So dropped stitches, which can unravel a fabric, rarely interfere with crochet work. This is also because of a second, perhaps less obvious, structural difference between knitting and crochet. In knitting, each stitch is supported by the corresponding stitch in the row above and it supports the corresponding stitch in the row below. In crochet each stitch is only supported by and supports the stitches on either side of it. If a stitch in a finished item breaks, the stitches above and below remain intact, and, because of the complex looping of each stitch, the stitches on either side are not likely to come loose unless put under a lot of stress.
Round or cylindrical patterns are simple to produce with a regular crochet hook, but cylindrical knitting requires either a set of circular needles or four or five special double sided needles. And free form crochet can create interesting shapes in several dimensions because new stitches can be made independently of previous stitches almost anywhere in the crocheted piece.
Knitting can be accomplished by machine, while many crochet stitches can only be crafted by hand. Although some crochet patterns can emulate the appearance of knitting, distinctive crochet patterns such as the Granny square cannot be simulated by other methods.
Crochet is more suitable than knitting for joining pieces of fabric and knit patterns for sweaters may incorporate crochet for finishing. Crochet can add borders or surface embellishment to both knit and crochet fabric. Crocheted fabric uses 1/3 more yarn than knitted fabric. Crochet produces a thicker fabric than knitting, and tends to have less "give" than knitted fabric. And, generally speaking, crochet technique produces fabric faster than knitting.
Crochet has been used by mathematician Daina Taimina in order to create a version of the hyperbolic plane. A paper model based on the pseudosphere was created by William Thurston, however, it was quite delicate. Daina Taimina used the art of crochet to create a strong, durable model, which received an exhibition by the Institute For Figuring.