The method of converting yarn into fabric by intermeshing loops, which are formed with the help of needles is known as knitting. There are two basic forms of knitting technology: Weft Knitting and Warp Knitting. Weft knitting is done with hands, and with machines. Warp knitting is done by machines only. In weft knitting, only a single yarn is required and the fabric consists of horizontal parallel courses of yarn. On the other hand, warp knitting requires one yarn for every stitch in the row, that is the course, and these yarns make vertical parallel wales. Warp knitting is resistant to runs, and is commonly used as a lingerie fabric. Weft knitted fabrics can be produced in either tubular or flat form. Weft knitted fabric is usually highly elastic and highly drapable, which makes it suitable for a wide range of apparel applications. The main advantage of warp knitted fabric is that it is not easy to unravel like weft knitted fabric. However, this fabric is not as elastic as weft knitted fabric. Let us now study in detail the two basic types of knitting:

• Weft Knitting
• Warp Knitting

Weft Knitting
The process of hand knitting is known as weft knitting and it can also be done by machines. In weft knitting, the work progresses back and forth, that is width-wise. In each cycle which is known as course, a new row of stitches is formed. In each row there may be a number of stitches depending upon the width of the fabric to be knitted. Each stitch of the row is built-up intermeshing with the previously held stitches of the previous row. The vertical row of stitches or loops hanging vertically from the needles is known as wale. Weft knitted fabric is produced in either flat or tubular form.

Types of Weft Knitted Stitches
There are three fundamental stitches in weft knitting:

• Plain-knit Stitch
• Purl Stitch
• Rib Stitch

Plain-Knit Stitch
The basic form of knitting is the Plain Knit. This stitch can be produced in flat knit, tubular, or circular forms. The flat knit is also called jersey stitch. In plain knitted stitch, each loop is drawn through other loops to the right side of the fabric. The loops form vertical rows, also called wales, on the fabric face, giving it a sheen, and crosswise rows, also called courses, on the back. The plain-knit stitch produces relatively lightweight fabric compared with the thicker fabrics produced by other stitches.

Purl Stitch
This stitch is also known as the links/links stitch. It is made on flatbed and circular machines by needles using hooks on both ends. The hooks alternately draw loops to the front of the fabric in one course, and to the back in the next course. It is a slow and costly technique. Purl-stitched fabric looks the same on both sides and resembles the reverse of the plain knit. Because the purl stitch has crosswise stretch and excellent lengthwise stretch, it is widely used in kids' and infant wear.

Rib Stitch
The Rib knitted stitch is produced either on a flat rib machine or a circular rib machine. Rib knitted fabric has alternating rows of plain and purl stitches constructed so that both the face and back of the fabric look alike. Rib construction is costlier because of the greater amount of yarn needed. Weft Knitted Fabric is usually highly elastic and highly drapeable and these two properties make the fabric suitable for a wide range of apparel applications. Weft knitted fabric is considered to be comfortable both for outer garments and undergarments.

Warp Knitting
While a weft-knitted fabric consists of horizontal parallel courses of yarn and requires only a single yarn, warp knitting requires one yarn for every stitch in the row or course. The basic feature of warp knitting is that these yarns make vertical parallel wales. It differs from weft knitting in that each needle loops its own thread. The term 'warp knitting' refers to machine knitting. The needles produce parallel rows of loops simultaneously that are interlocked in a zigzag pattern. The stitches on the face of the fabric appear vertically and the stitches at the back appear horizontally as floats at a slight angle. These floats are also called Laps or Underlaps, and are a distinguishing identification of warp knits.

Types of Warp Knitted Stitches
There are six fundamental stitches in warp knitting:

• Tricot Knit
• Milanese Knit
• Simplex Knit
• Raschel Knit
• Ketten Raschel Knit
• Crochet Knit

Tricot Knit
Tricot fabric is soft, wrinkle resistant and has good drapability. Tricot knits are used for a wide variety of fabric weights and designs. Some examples of tricot fabric are lingerie, loungewear, sleepwear, blouses, shirts, dresses, slacks etc.

Milanese Knit
The milanese stitch produces a fabric very similar to tricot. It can be identified by the fine rib on the face and a diagonal pattern on the back. However, milanese fabric is superior to tricot in smoothness, elasticity, regularity of structure, split and tear resistance.

Simplex Knit
Simplex fabric is made of fine yarn and is relatively dense and thick. It is a small part of warp knit production. Simplex fabric is used to make gloves, handbags, sportswear and slip covers. Eyelets and other openwork can also be produced on the simplex machine.

Raschel Knit
The raschel knit ranks in importance of production with tricot but it make varieties of products ranging from veilings, laces, power nets for foundation garments, to carpets. Raschel knitting is done with heavy yarns and usually has an intricate lace-like pattern.

Ketten Raschel Knit
This is also known as the chain raschel. The machine can be equipped to produce raised pattern effects in one or more colors. The fabric is finer, has a better hand, superior elasticity and cover.

Crochet Knit
This basic stitch is used in hand-crochet. This construction is used in a wide variety of fabrics ranging from nets and laces to bedspreads and carpets.