Increases (inc) are used to shape your knitting and to create lace patterns. There are many ways to make an increase; we've listed a few standard methods below. Many pattern instructions specify which type of increase to use; others do not.
It's important to learn how each increase affects the appearance of your work so you can use the appropriate method. Make small knit swatches and practice each increase method listed here. Label them, and keep them for future reference. Avoid making increases and decreases in the edge stitches because they affect the ability to make a smooth seam when finishing. Make increases or decreases at least one stitch in from the edge stitches.
Yarn Over (yo)
A yarn over is the basis of most lace patterns and is very simple to make. In fact, many new knitters make yarn overs completely by accident (but in those cases it's called a hole, not lace). When moving the yarn from the front or the back of your work, you would normally be very careful to put the yarn between the needles and not over it (which would create an extra loop on the needle). To make a yarn over when knitting, bring the yarn to the front of the work and then knit the following stitches as instructed (fig. 16a). On the next row, work into the front loop of this strand (yarn over) as you would any other stitch, transferring it from the left needle after it is knitted.
Knit 1 in the Front and Back Loops (k1f&b)/Bar Increase
This is one of the most visible increases in stockinette stitch -- it leaves a little bump that looks like a purl stitch. Use it decoratively, or use it when the purl bump is part of a stitch pattern. The bar increase is one of the easiest to make and is usually a favorite with knitters.
To make it, knit the front loop, but don't remove the stitch from the left needle (fig. 16b). Knit into the back loop of the same stitch (fig.16c).
Make One (m1)
These increases are made simply by knitting into the horizontal strand between stitches on the right and left needles. One method creates a left-leaning increase, meaning that the front strand of the increase slants to the left. The other method leans to the right. This is called paired increases.
To make a left-leaning increase:
Step 1: Insert the left needle from front to back under the strand (fig. 16d).
Step 2: With the right needle, knit into the back of the strand (fig. 16e).
Step 3: Slip the strand off the left needle. You now have 1 new stitch (an increase) on the right needle. Note how the front strand of this new stitch leans toward the left (fig. 16f).
To make a right-leaning increase:
Step 1: Insert the left needle from back to front under the strand (fig. 16g).
Step 2: Knit into the front of the strand (fig. 16h).
Step 3: Slip the strand off the left needle. You now have 1 new stitch (an increase) on the right needle. Note how the front strand leans toward the right (fig. 16i).
Let's move onto knitting decreases on the next page.