Ridged half double crochet infinity scarf from a mandala yarn cake

Back-loop half double crochet ridges this looped scarf into a thick, spongy band — a one-skein infinity wrap with no seam.

Skill: Intermediate
Time: 4-6 hours
Hook: 10 mm
Yarn: Worsted
Rounds: 4

Jump to the rounds Pin it

About this pattern

Working half double crochet into the back loop only, under the V of each stitch, leaves the front loop sitting on top as a raised horizontal cord, so the surface reads as ribbed rather than flat the moment you run a hand across it. Paired with a size N/10mm hook, the fabric stays loose and a little spongy, with visible gaps between stitches instead of a tight, solid weave.

The scarf's endless loop design makes it versatile — wrap it once, twice, or let it drape for a relaxed look. The shape is a single continuous loop, built from one long chain joined at the start and never cut until the last stitch, with the gradient from the Mandala cake shifting color as it winds, no clasp and no ends to tuck.

The swatch in numbers

Rounds: 4
Level: Intermediate
Time: 4-6 hours
Hook: 10 mm
Yarn: Worsted

The yarn and the hook

Mandala yarn cake (Andorian was used for its gradient effect)
Size N 10 mm crochet hook
Scissors
Tapestry needle

Stitches, spelled out

ch chain; hdc half double crochetDense; sc single crochetDense; sl st slip stitch.

Main Pattern

Work in continuous rounds without joining after Round 1.

Insert hook into the back loop under the "V" of the stitch for each half double crochet.

Let the yarn change colors naturally as you work through the skein.

Round 1Make a slip knot by holding the shorter piece of yarn in your right hand, folding the longer piece over to create a loop, pushing the longer piece up through the loop, and pulling the short piece to tighten the knot; insert your crochet hook into the loop and tighten it around the hook; chain 120 (yarn over and pull through the loop on your hook to create a chain, repeat until you have 120 chains); run your fingers down the chain to ensure it's straight; insert your crochet hook into the first chain and yarn over, pulling through both loops on your hook to create a slip stitch, forming a circle. (120)

Round 2Chain two; yarn over, insert your hook into the top loop of the next chain space, pull yarn through to have three loops on your hook, yarn over and pull through all three loops to complete a half double crochet; continue making half double crochets in each chain space around.

Round 3Work continuously in the round without joining; turn your work slightly to the side; insert your hook into the back loop under the "V" of the stitch; yarn over, pull up a loop (three loops on hook), yarn over, pull through all three loops; repeat half double crochets into the back loop of each stitch around; continue until you finish the entire skein, letting the yarn change colors naturally.

Round 4Switch to single crochets for the last round as you near the end of the yarn, working into the back loop for the single crochets; tie off the yarn by making a knot in the first stitch of the last round.

Putting the pieces together

Step 1Snip the yarn with scissors.

Step 2Pull the yarn through to secure and optionally make a second knot.

Step 3Use a tapestry needle to weave in any loose yarn ends.

Close-ups

Ridged half double crochet infinity scarf from a mandala yarn cake — photo 2

Ridged half double crochet infinity scarf from a mandala yarn cake — photo 3

Ridged half double crochet infinity scarf from a mandala yarn cake — photo 4

Ridged half double crochet infinity scarf from a mandala yarn cake — photo 5

Questions people ask

Why does Round 3 specify working into the back loop only?

Working under the back loop, the V of the stitch, leaves the front loop sitting on the surface as a raised ridge, so each round shows up as a distinct textured ring. That ribbing is what gives the band its corded surface rather than a flat, smooth one.

Why is there no join after Round 1 but the first round is joined?

Round 1 is joined with a slip stitch to close the chain into a circle and set the loop. Rounds 2 through 4 then run continuously with no join, so the spiral of stitches has no seam line and the color blends across rounds without a visible break.

How long will the finished loop be before wearing it as an infinity scarf?

Length comes directly from the 120-chain foundation, so the loop's finished circumference matches that chain count once Round 4 is tied off. No length is added or taken away in later rounds, so check the chain count carefully before moving on.

New patterns, as they are filed

One short email when a batch lands, with the feel of each.