Draft
I-Cord Cast On
A cast on with an i-cord running along the edge.
7 min videoGood for decorative edges, blankets, scarves
The i-cord cast on is a decorative cast on that puts a small knitted tube along the bottom edge of your work. It pairs with i-cord up the sides and an i-cord bind off at the top for a finish that matches all the way round, and it suits blankets, scarves and anything where the edge is on show.
You make it by knitting a short i-cord of four stitches and increasing into the first stitch on every pass, so each round of the cord leaves one new stitch on the needle.
There are two things to watch. If you do not knit the first two stitches of every pass very tight, the stitches along the edge stretch long and are hard to fix afterwards. And when you close the cord at the end there is a small gap in the corner to deal with.

1 Cast on four stitches
Start with a slip knot and cast on four stitches any way you like. Here it is the knitted on cast on: knit into the stitch, draw the loop through and place it on the needle, three times.

2 Knit the four stitches
Knit across those four stitches as normal.

3 Slip them back
Slip the four stitches back onto the main needle without working them, so you are ready to knit the same stitches again.

4 Knit front and back, very tight
Knit the first stitch again but leave it on the needle, then knit it through the back loop, the same as a knit front and back increase. Pull these first two stitches really tight, tighter than you normally would. Do not pull the work away from the needle for slack. Keep it snug against the needle and come straight back into the stitch.

5 Knit the other three
Work the remaining three stitches in the row as normal. These do not have to be as tight.

6 Slip four back again
Slip the last four stitches back to the main needle. The extra stitch stays behind on the working needle. That is your first cast on stitch.

7 Then keep going
Repeat: knit front and back into the first stitch and pull tight, knit the next three, slip four back. Each time round adds one stitch to the cast on. Watch for the yarn splitting on that tight first stitch, especially with cotton.

8 To finish, knit two together twice
When you have the stitches you need, knit two together, then knit two together again.

9 Slip back and knit those together
Slip those two stitches back to the main needle and knit them together. That closes the end of the cord and finishes the row. If the edge stitches look long, you did not pull them tight enough. Twisting them by knitting through the back loop on the next row helps a little.