Around 1/4 to 1/3 of a 50g ball of sock yarn. I used Paton's Kroy leftovers.
2.25mm/US 1 knitting needles.
A needle threader or a small piece of thin fishing line.
7 sts and 10 rows to 2.5cm/1" measured on St st in the round.
Thread beads onto yarn. I used a piece of fishing line to do this. Wrap your line around the yarn and thread the ends through each bead then pull bead down the line and onto yarn. If you are using two colours of beads like I did, alternate the first three, then do two of each in alternating colours for 11 repeats, then alternate the remaining ones. So your colours end up like mine did. Otherwise you will get one colour on each side of the steam. Although that could give it a nice shadow effect.
Cast on 64 sts (16 on each needle). Join to knit in the round.
Knit in 2x2 ribbing for three rounds. Needles 1, 3 and 4 are in ribbing for the entire pattern. St st and chart on needle 2 only. Knit a plain round on N2, only, after each beaded round. Once you have finished the chart, knit another 3 rounds of 2x2 ribbing. Cast off with a stretchy bind off. I used a loose sewn bind off.
How to read the chart: start at the bottom and read right to left making sure to remember the plain round between each beaded round. The plain rows are not marked on the chart. Each empty square is a knit stitch and each coloured square is where you place a bead against the previous stitch, then knit 1. The beads will end up on the bar between the stitches and want to sit on the purl side so when you are finished, turn it inside out and it's ready to go.
The finished sleeve will fit most take out coffee cups. I like the billowing look the purl side gives the steam, but if you prefer using a crochet hook to add your beads as opposed to threading them on the yarn, you can just as easily do that. Your beads will end up on the knit side. You'll need to add a plain row on N2 before starting the chart and you'll have to move the chart to the right one column to centre it better. I'd also eliminate the plain row on N2 at the top of the chart and just begin the ribbing.
I only put beads on one needle, since they may heat up on the cup. Putting them on one needle gives you a pretty sleeve and still protects your hands from the heat.