The first line of instruction in every knitting pattern is basically the same: the knitter is required to “cast on,” or make a foundation row of a specified number of stitches before beginning the fun part of the pattern. After all, you have to start somewhere. The one problem is that not all patterns tell you which cast-on method to use.
The basic slip-knot is the first building-block for casting on; just form a loop by crossing your yarn over itself, and form a second loop by drawing a length of yarn from the tail in the back of the first loop, pulling it through the hole from front to back (do not draw a yarn end through the hole). Tighten the first loop around it, and there you go! This knot also counts as your first stitch.
If your cast-on edge is too tight, the edge of your knitted piece will not lay flat, so be sure to cast on loosely. If you are unsure of your tension, you can cast on using a needle one or two sizes larger than you will use on the rest of your piece, and knit onto your project needles in your first row.
There are several methods to casting on, however, not all patterns are explicit in telling you which one is best. Here is a sampling of some popular cast-on methods to help you make the right decision when you begin your next knitting project.
Knitted cast-on: This method is perfect for both beginners and seasoned veterans who will be casting on a large number of stitches at once. While it does not provide the prettiest edge, it is stable and easy to learn. This method involves going through the motions of the knit stitch, except the knitted loop is placed back onto the left needle. By the time new knitters are ready to start knitting, they have already practiced the knit stitch in their cast-on row. This method is good for a long cast-on row since there is no tail to estimate and measure (see the Long Tail cast on, below). Here is a great video from Lion Brand, demonstrating the knitted cast-on.
Cable cast-on: This method is similar to the knitted cast on. In fact, the first two stitches are completed exactly the same way. In the following stitches, the needle is inserted between the last two stitches on the left needle, instead of into the end stitch on the left needle, to draw the yarn through to the front of your work. This provides a more elastic edge, is also ideal for a large number of stitches, and it has an attractive look if your stitches are consistent. Sarah E. White’s explanation of this cast-on will help you if this is a method you would like to try.
Long-tail cast-on: While this method takes a bit more planning than the knitted cast-on, the edge is more stable and attractive, since you are essentially knitting a row onto your needle. It is also more elastic, making this method ideal for ribbing and for anything fitted. The key is making sure you measure a long enough tail; your tail is the working yarn of this cast-on. While there are several methods to calculating the appropriate tail length, the most reliable method is to cast on ten stitches using your project yarn and needles, pulling them out, and measuring how much yarn-tail you used. You can calculate the amount of yarn needed, based on how much yarn you used for ten stitches. Knittinghelp.com has a comprehensive tutorial on this method, found here.
Backwards-loop cast-on: If you are adding a buttonhole in the middle of your project, or you only need a few stitches, the backwards-loop method is an excellent option. This method provides a less stable edge, so it is not recommended as a long foundation row, but it is a very quick method of casting on. From your slip knot on the needle, all you do is loop the yarn around the needle so the yarn going to the ball is anchored between the loop and the previous stitch. The Lion Brand website has a good video demonstration of this method.
Provisional cast-on: Sometimes, patterns will call for a provisional cast-on. Normally, you will see this on patterns where the bottom edge of the item is not the starting point of your knitting. A provisional cast-on is used when live stitches will be needed at a later time to knit in the opposite direction, such as scarves knitted in identical halves from the middle, and reversible items. This method is also excellent for when you will be adding a decorative edge to your knitting. Eunny Jang’s demonstration on Knitting Daily shows a few variations of this method perfectly.
There are many, many other methods which are ideal for more specific edges. The tubular cast-on, for instance, is a more advanced method which results in a stunning edge for K1P1 ribbing. A triangular shawl knit from the neck will also have a specific, seven-stitch foundation row involving knitting into the side of a garter-stitch strip, so the project stays stable as it grows larger. The methods above, however, encompass the vast majority of your projects if the instructions do not specifically tell you which one to use. When in doubt, the employees at your local yarn shop are an excellent resource of advice for casting on, based on which project you are aiming to complete. Similar to breakfast being the most important meal of the day, your foundation or cast-on row is the most important row of your knitting project. Be sure to choose wisely.