The long-tail cast on is the default start for hats, scarves and sweaters. It makes a firm, elastic edge with a neat chain along the bottom, and it needs no second ball of yarn, because the cast-on stitches are made from a long tail left at the start. The catch is that you have to guess the tail length before the first stitch, and a wrong guess means starting again.
Estimating the tail
The tail must hold the entire cast-on edge. A rule that works for most yarns and needles: allow about 2.5 cm of tail per stitch for fine yarn, and about 3 cm per stitch for worsted and bulky. So 100 stitches need about 2.5 to 3 metres. A quicker check is to wrap the yarn around the needle once for each stitch, counting wraps for the first 10, then multiply that length and add a hand's length for the tail end.
If you are unsure, cast on a quarter of the stitches, measure the tail used, multiply by four, and add a little extra. This is a better guide than any formula because it includes your own tension.
| Stitches | Fingering weight | Worsted weight |
|---|---|---|
| 40 | about 1 m | about 1.2 m |
| 80 | about 2 m | about 2.4 m |
| 120 | about 3 m | about 3.6 m |
| 200 | about 5 m | about 6 m |
Thick needles need more tail, since each stitch wraps a bigger loop.
Making the cast on
- Make a slip knot leaving your measured tail and place it on the needle. This counts as the first stitch.
- Hold the needle in your right hand. With your left hand, put the thumb in the tail loop and the index finger in the working yarn, forming a slingshot shape.
- Put the needle under the loop around the thumb from below.
- Go over the yarn on the index finger and take it back down through the thumb loop.
- Release the thumb loop and pull the tail to snug up the new stitch.
- Repeat, keeping the stitches firm but not so tight that the needle will not move.
The first row after the cast on is worked with a different texture depending on the pattern. The stitch database lists the cast on with the stitches that usually follow it.
Edges that are too tight
A tight edge does not stretch, pulls the fabric in and causes the bottom of a hat to flare out above it. Causes and fixes:
- Stitches pulled too firmly. Leave a finger's width of slack between stitches and let them sit loosely on the needle.
- A needle that is too small. Cast on over two needles held together, and remove one before the first row. The stitches then are the size of the larger gauge and the edge has more give.
- Wrong thumb tension. Spread the thumb slightly as the loop is made, so each stitch has room.
Edges that are too loose
If the edge is sloppy and flared, the usual cause is casting on loosely to compensate for a previous tight edge. Keep the stitches even and use the same needle for the cast on as for the body; if the body needs a smaller needle for a rib, cast on with the rib needle. A loose edge is also fixed by working the first row into the back of each cast-on stitch, which twists them and tightens the fabric.
Uneven stitches
Look at the bottom edge. If stitches differ in size, the thumb loop tension was not constant. Pulling the tail after every stitch to set the loop makes each stitch the same size. Counting as you go, by marking every ten stitches with a removable marker, catches miscounts, which are more common than tension errors.
The two sides
The front of a long-tail cast on has a row of stitches that look like knit stitches; the back shows a line of purl bumps. For the cast on to be the right side you want, the first row should be worked on the wrong side if the pattern expects a clean edge facing out. Patterns usually say whether the cast on row counts as a row, and whether to begin with a knit or purl row.
Casting on in the round
For a hat worked in the round, cast on all the stitches, check that they are not twisted around the needle, and join by working the first stitch of the round. Twisted stitches cannot be fixed later. The hat designer in the tools section gives the cast-on count for a head size and gauge, so you can check the tail length against the stitch total before starting.
Other cast ons
- Cable cast on: easier to start with, firmer edge, no tail needed.
- Knitted cast on: soft edge, good for adding stitches at the end of a row.
- Provisional cast on: a temporary edge that can be unzipped later to knit in the other direction.
The long-tail cast on remains the best all-purpose choice for ribbing and hems, since it stretches with the fabric and has a consistent look across the piece.