Edges and joins between fabrics

The initial and final edges of a knitted fabric are known as the cast-on and bound-off edges. The side edges are known as the selvages; the word derives from "self-edges", meaning that the stitches do not need to be secured by anything else. Many types of selvages have been developed, with different elastic and ornamental properties. Vertical and horizontal edges can be introduced within a knitted fabric, e.g., for button holes, by binding off and re-casting on again (horizontal) or by knitting the fabrics on either side of a vertical edge separately. Two knitted fabrics can be joined by embroidery-based grafting methods, most commonly the Kitchener stitch. New wales can be begun from any of the edges of a knitted fabric; this is known as picking up stitches and is the basis for entrelac, in which the wales run perpendicular to one another in a checkerboard pattern. In knitting, casting on is a family of techniques for adding new stitches that do not depend on earlier stitches, i.e., stitches having an independent lower edge. In principle, casting on is the opposite of binding off, but the techniques involved are generally unrelated. Casting on can also be decorated with various stitch patterns, especially picots. The cast-on stitches can also be twisted clockwise or counterclockwise as they are added to the needle; this is commonly done for the single cast-on described above to give it a neater, more uniform look. Casting on is sometimes done with two needles, or a needle of larger size; the extra length of yarn in each stitch gives the edge more flexibility. When casting on at the beginning, one end of the yarn must be secured to the knitting needle by knotting it, usually with a slip knot. This knot is unnecessary when casting on in the middle of the fabric (e.g., when making the upper edge of a buttonhole) since the yarn is already secured to the fabric. The original slip knot can also be pulled out (after a few rows have been knitted) without damaging the knitted fabric. Once one loop has been secured around the needle, others can be added by several methods. Knit-on cast-on Perhaps the most straightforward method, in which a new loop is drawn through the previous loop and then added to the needle. However, this method is deprecated for giving an untidy edge. It can also be done in a purl version, or even a rib version. Cable cast-on A closely related technique, in which a new loop is drawn through the space between the two previous loops and then added to the needle. This edge is firm and has a neat, corded look; although it may be too bulky with thick yarns. Single cast-on An even simpler method, also called the simple cast-on or "back

ard loop cast-on," which involves adding a series of half hitches to the needle. This creates a very stretchy, flexible edge. It is a common approach for adding several stitches to the edge in the middle of a knitted fabric, but it is difficult to knit from and make even. A variation is the twisted simple cast on, where you twist the new loop around your thumb, with the yarn going around the back of your thumb to the front as in the simple cast-on, but picking up the new loop from the back side of the loop. This is tighter and neater, but has less elasticity. Double cast-on A common method, in which all the loops are made with one yarn, while the other end (the dangling end from the original slip knot) is used to secure the base of each loop. This method is also called the "knit half-hitch cast on" or the "long-tail cast on." Although popular, this method requires that the knitter estimate the length of the dangling yarn before the stitches are cast on; if the dangling yarn is too short, the knitter will run out of yarn with which to secure the stitches before the full number of stitches have been cast on. In that case, the knitter will have to pull everything out, re-position the slip knot to give a longer tail, and begin anew. Despite this shortcoming, it's a good all-around method for casting on. Another variation for this method is to use two different yarns, one the main yarns that you are using for your project, and the second a piece of contrasting waste yarn. You attach the two with a slip knot, and then using the waste or contrast yarn as your long tail, start your row. This is useful if you need to pick up stitches on your cast on edge in order to knit in the opposite direction. You can also use it decoratively, making the contrast or waste yarn a part of your pattern design. To execute it, you start by figuring out how much yarn you expect your cast-on row to require and pulling out that amount of yarn. Once you have that, put a slip knot on the needle (this is not absolutely necessary, since the first cast-on stitch will create a slip knot for you in the process, but it is generally more secure to start with a slip knot). Hold the needle in your right hand and the yarn in your left, with the long tail pulled around your thumb and hanging in front, and the yarn from ball around your first or second finger, with the ball tail heading toward the back. Once you have that, take the needle under the front of the long tail, picking up a half hitch, then back to the yarn over your finger from the top side of the yarn, pulling the loop through the half hitch you had formed. This cast on can also be done in a purl and a twisted stitch version as well.