When you need a cast-on that make you look like a pro AND gives you tons of stretch (think sleeve cuffs and top-down socks), it's time to get tubular.
The first few rows of this gorgeous cast-on are created with double knitting (two layers of fabric knit simultaneously). This forms a small, unnoticeable "tube" at the edge, which gives the hem both elasticity and stability. It also looks totally seamless.
As you can see in the image above, the tubular cast-on has an edge that looks like it's part of the rib — the rib flows right to the edge. The long-tail cast-on, by contrast, binds the rib. This means the tubular cast-on edge is more elastic than the long-tail cast-on.
Waste Yarn Method
This is our favorite way to work the tubular cast-on — no fancy techniques required. Start with some scrap yarn and cast on with your favorite method, then work some foundation rows in your project yarn. Remove that waste yarn, and you've got a beautiful edge. This method works for knitting in the round, too!
1x1 Rib Tubular Cast-On Instructions
1. Cast On Your Waste Yarn
Select a waste yarn in a contrasting color to your project yarn (so it will be easy to see). The yarn should have a similar gauge to your project yarn and a smooth texture to avoid stray fuzz when you remove it.
Using the waste yarn, cast on half the number of stitches you need, plus one. Use any cast-on method you prefer — since we're going to eventually remove these stitches, the method isn't important.
We want 24 stitches in our final rib, so we cast on 13 stitches (12 + 1) using a long-tail cast-on .
2. Work Foundation Rows
These are the rows that will create the double-knit tube that gives your edge elasticity.
Switch to your project yarn.
Row 1: *Knit 1, yarn over . Repeat from * to the last stitch, then knit the last stitch.
By the end of this row, you'll have the number of stitches you want in your rib, plus one. Here, we increased 13 stitches to 25, so we have 24 + 1, which is perfect!
Row 2: *Slip first stitch purlwise with yarn in front. Move yarn to back and knit the yarn over. Repeat from * to last stitch. Slip last stitch.
The photo above shows a stitch being slipped with yarn in front. Note the previous stitch is a knitted yarnover.
Here is a close-up of the completed Row 2. Note the knitted yarn overs alternating with the slipped purlwise stitches.
Row 3: *Knit with yarn in back, slip 1 purlwise with yarn in front. Repeat from * to last stitch. Knit last stitch.
You may notice that Row 3 is the opposite of Row 2. You are knitting the stitches you slipped in Row 2 and slipping the stitches you knit that appear as purl stitches on this side of the fabric.
As you finish Row 3, you'll start to see how the edge will form.
Row 4: *Slip first stitch purlwise with yarn in front. Move yarn to back and knit the next stitch. Repeat from * to last stitch. Slip last stitch.
Note that this is the same as Row 2 except that you aren't knitting into a yarn over.
Row 5: Repeat Row 3.
That completes the double knit foundation rows! Congrats!
3. Start Ribbing
Row 6: Start your 1x1 rib. Remember you are on the wrong side of the fabric, so start with p1, k1, and purl the final stitch.
What do you do with the extra stitch? You can keep it as selvage or for joining if you are knitting in the round. If you really don't want it, you can decrease it away.
Continue with your 1x1 rib until you have completed the ribbing required by your project.
4. Remove the Waste Yarn
You can remove the waste yarn at any time after you start the ribbing (note in our pictures, we jumped the gun and didn't knit any ribbing before we started cutting...oops!).
There are two methods for removing waste yarn: cutting or unraveling the yarn. They both take time, so be patient! Seriously: if you try to rush this part, you might have to start over. So, deep breaths, and go slow.
Cutting the waste yarn
First, pull very gently on the cast-on edge so the loops below the yarn overs are safely away from the project rows.
Very carefully snip each cast-on loop below the yarn overs.
Then pick out the pieces of waste yarn.
Unraveling the waste yarn
Tease the waste yarn from the cast-on edge by picking at the yarn and pulling the end through the project loops. Note that the yarn will not just unravel like in a provisional cast-on, so don't pull on it! This type of removal might deform the stitches if you yank too hard.
2x2 Rib Tubular Cast-On Instructions
Casting on for 2x2 is very similar to casting on for 1x1 rib. So similar, in fact, that the foundation rows are worked exactly the same. The magic happens on your final foundation row, setting you up for a 2x2 rib.
These instructions assume you are starting out with a knit rib and ending with a purl rib. If you are starting out with purl, you will need to adapt the instructions accordingly.
1. Cast On with Waste Yarn
Follow Step 1 as in the 1x1 tutorial.
2. Work Foundation Rows
Complete Rows 1 through 4 exactly as in the 1x1 tutorial.
Don't try to change anything for the 2x2 rib yet or you will wind up with a mess of unraveled stitches (we speak from experience!).
After Row 1, you should have the number of stitches you need in multiples of 4 (for the 2x2 rib) plus 1 stitch. We will address the extra stitch in Row 5.
Row 5: Now we need to reposition the stitches to give you your 2x2 rib.
1. Knit the first stitch.
2. Slip the next stitch, a purl stitch, onto a cable or dp needle and hold to back of work.
3. Knit the next stitch from the left needle.
4. Purl the stitch from the cable needle.
5. Purl the next stitch from your left needle.
Continue with these five steps until you get to the last two stitches. Purl the last two stitches together (unless you want the last stitch for the selvage).
You now have your stitches in the correct order for 2x2 rib and have absorbed the extra stitch.
3. Begin Ribbing
Row 6: Start your 2x2 rib and continue according to your pattern. Remember that you are on the wrong side of your fabric.
4. Remove the Waste Yarn
Follow the instructions for 1x1 tutorial.
Tubular Cast-On in the Round
1. Using your waste yarn, cast on to your circular needles. (This will not work with tubular cast-on techniques that require straight needles.)
2. Work your foundation rows with your project yarn, but do NOT join. Knit the foundation rows back and forth on the circular needles as if you were knitting a flat project.
3. Start your ribbing. Slip the first stitch so you can use it for the join and then follow the ribbing pattern by knitting the knit stitches and purling the purl stitches. At the end of the round, join in the first round by purling (or knitting) the last stitch together with the first slipped stitch.
4. When the project is complete, seam the foundation rows before the join.
Magic Cast-On Variation
Skip the waste yarn and double knitting altogether and use Judy's Magic Cast-On instead!