Wrapped in Rainbows: A Trinity Stitch Baby Blanket (Crochet)

There is something quietly magical about making a baby blanket. You sit down with yarn and a hook, and a few hours later you have something that will be draped over a sleeping child, tucked into a stroller, brought home from the hospital, photographed a hundred times, and maybe — if you’re lucky — kept for decades. The stakes feel high in the best possible way. That’s why choosing the right stitch matters so much, and the trinity stitch is one of those rare techniques that delivers on every front: it looks stunning, it works up faster than it appears, and it creates a fabric that is dense enough to be warm but soft enough for newborn skin.

This pattern is called Wrapped in Rainbows because it was originally designed with a gradient colorway in mind — that slow, joyful wash of color moving from one end of the blanket to the other, like early morning light shifting through a window. But the name also carries a deeper meaning. Every stitch you make is a small act of wrapping someone in love. Whether you’re making this for your own baby, for a shower gift, or as a keepsake for someone who means the world to you, the blanket holds that intention in every row.

Let’s talk through everything you need to know to make this project from start to finish.

What Makes the Trinity Stitch So Special?

Before you cast on a single chain, it helps to understand why the trinity stitch was chosen for this design rather than a more common option like a shell stitch or a simple double crochet.

The trinity stitch gets its name from the way it works in groups of three. Each cluster is made by pulling up loops and drawing them together, which creates a dense, almost fabric-like texture with a subtly raised, bobble-adjacent surface. Unlike true bobbles, which can be bulky and uneven, the trinity stitch creates a uniform pattern of clusters that sits flat without distorting the fabric. The result looks almost like a knitted moss stitch or a woven textile, which tends to photograph beautifully and impresses people who have no idea how it was made.

It is also, from a practical standpoint, an incredibly sensible choice for a baby blanket. The tight cluster construction means there are no large holes or open gaps for tiny fingers to catch in. The fabric has natural body and warmth without being stiff. And because the stitch uses a repeated, rhythmic motion, it becomes meditative once you get into your groove — the kind of project you can work on while watching a movie or sitting with friends.

Materials You Will Need

To make a blanket that measures approximately 30 by 36 inches, which is a generous lapghan size appropriate for a crib, stroller, or tummy time mat, you’ll want to gather the following.

For yarn, you’ll need roughly 1,000 to 1,200 yards of DK or light worsted weight yarn. If you’re doing a gradient or rainbow colorway, plan for 150 to 200 yards per color, which gives you room for six to eight color transitions. Some of the most popular choices for baby blankets include Paintbox Simply DK, Lion Brand Baby Soft, Caron Simply Soft, and Drops Safran. If you want maximum softness and a slight sheen, a cotton-bamboo blend is a lovely option. Avoid anything scratchy or that contains materials that might irritate sensitive skin.

For your hook, a size 5mm (US H/8) works well for most DK-weight yarns at a gauge that creates good stitch definition without being too loose. That said, always check your gauge before diving in.

You will also want a tapestry needle for weaving in ends, scissors, and stitch markers if you find them helpful for keeping track of your stitch count.

Gauge and Sizing

For this pattern, you’re aiming for roughly 14 trinity stitch clusters and 16 rows to measure four inches. Because the trinity stitch is a cluster-based stitch rather than individual stitches, gauge is measured in clusters per inch rather than stitches per inch.

If your gauge is looser than this, go down a hook size. If it’s tighter, go up. It’s worth taking a few minutes to make a four-inch swatch before starting the full blanket because the trinity stitch uses quite a bit of yarn and ripping back several rows is no fun at all.

A finished blanket of 30 by 36 inches is ideal for a baby’s first year. If you want a smaller receiving blanket, you can reduce your starting chain by working in multiples of two plus a turning chain. If you want a larger toddler blanket, simply add more chains at the start and plan for additional yardage.

Understanding the Trinity Stitch

If you’ve never worked the trinity stitch before, it might look intimidating on paper but it becomes very intuitive once you’ve done a few rows. Here is how it works.

The stitch is based on a cluster that uses three loops pulled up together. You insert your hook into the stitch, pull up a loop, then insert into the next stitch and pull up another loop, then insert into the stitch after that and pull up a third loop. You then yarn over and draw through all four loops on your hook (the three you just pulled up plus the one that was already there). That completes one trinity stitch cluster.

Each row is offset from the one before it, which creates that diagonal, interlocking texture. The first stitch of each new cluster begins in the same stitch where the previous cluster ended, which is what gives the pattern its seamless, almost knitted look.

On the right side rows, you’ll work your clusters from left to right. On the wrong side rows, you’ll turn and work back across. Because the pattern is reversible, both sides look nearly identical, which is one of its great virtues — there’s no “wrong side” to accidentally show.

The Pattern

Abbreviations used:

ch = chain, sc = single crochet, tr-st = trinity stitch cluster, sl st = slip stitch, sp = space, RS = right side, WS = wrong side.

Starting chain: Chain 101. (This gives you 100 working chains plus one turning chain. The number of working chains should always be even for this pattern to work out symmetrically.)

Foundation row (RS): Insert your hook into the second chain from the hook and pull up a loop. Insert into the third chain and pull up a loop. Yarn over, draw through all three loops on your hook to complete your first cluster. Chain one. Insert hook into the same chain you just used for the last part of the previous cluster, pull up a loop. Insert into the next chain and pull up a loop. Insert into the chain after that and pull up a loop. Yarn over, draw through all four loops. Chain one. Repeat from to across until you reach the last chain. Work one single crochet into the last chain to anchor the row. Turn.

Row 2 (WS): Chain one. Work one single crochet into the first stitch. Insert hook into the same stitch, pull up a loop. Insert into the next ch-1 space, pull up a loop. Insert into the top of the next cluster, pull up a loop. Yarn over, draw through all four loops. Chain one. Repeat from to across. End with one single crochet into the turning chain from the previous row. Turn.

Row 3 (RS): Repeat Row 2.

Continue working Row 2 and Row 3 alternately until your blanket reaches your desired length. Because both rows use the same basic construction but are offset by one cluster, you can simply repeat the same row instructions after the foundation row without having to think about right side versus wrong side orientation.

Working With Multiple Colors

The Wrapped in Rainbows colorway is what really makes this blanket come alive, and the great news is that changing colors in the trinity stitch is easier than it looks.

The cleanest way to change colors is to make your color switch at the end of a row, during the very last yarn-over of the last stitch. When you’re drawing your final loop through on the last cluster of a row, use your new color for that final pull-through. This carries the new color up cleanly and means your turning chain is already in the new shade.

For a gradient blanket, you might work about six to ten rows in each color before switching, depending on how gradual or dramatic you want the transitions to feel. A blanket with six colors and ten rows each will have a bold, clearly defined rainbow look. A blanket with eight colors and fewer rows per color will feel more like a watercolor wash.

Popular rainbow colorway options include a classic ROYGBIV progression (red, orange, yellow, green, blue, indigo, violet), a soft pastel version of the same, a gender-neutral earth tone spectrum moving from cream through sand to terracotta to deep brown, or a monochromatic ombre where you work from a pale tint down to a deep saturated shade of a single color. There is no wrong choice. Trust your instincts and what you know about the person this blanket is going to.

When you cut your yarn at a color change, leave a tail of at least six inches and weave it in diagonally through the backs of several stitches so it won’t work its way loose over time. Baby blankets get washed frequently, so secure those ends well.

The Border

A simple border pulls the whole blanket together, softens the edges, and gives it that finished, professional look. For this pattern, a single crochet border works beautifully without adding too much bulk or competing with the texture of the main body.

Once your blanket has reached its full length, do not fasten off. Instead, rotate your work 90 degrees and begin working single crochet stitches evenly along the side edge, placing approximately one stitch for every row end. When you reach a corner, work three single crochets into the corner stitch to turn the edge neatly. Continue around all four sides of the blanket, working three single crochets into each corner, until you arrive back at your starting point. Slip stitch to join and fasten off.

For a slightly more decorative border, you can add a second round of reverse single crochet (also called crab stitch) after the first round. The crab stitch creates a tightly coiled, rope-like edge that looks intentional and neat, and it’s worked in the opposite direction to regular single crochet, which is what gives it that twisted texture. It might feel awkward the first time you try it, but it moves quickly once you get the rhythm down.

If you want to add a pop of contrast, work your border round in a coordinating color rather than the yarn from the last row of your blanket. A dark navy against a pastel rainbow, or a bright white against an earth tone palette, can make the blanket look really polished.

Caring for Your Finished Blanket

Baby items need to be washable, full stop. Before you begin your project, check the care label on every yarn you plan to use and make sure it can be machine washed. Even if the yarn is superwash wool, most caregivers will appreciate a blanket that can go through a regular cycle without ceremony.

For acrylic and acrylic blend yarns, machine wash on a gentle cycle in cold water and tumble dry on low. For cotton or cotton-blend yarns, machine wash on a gentle cycle and lay flat to dry to prevent stretching. For anything with wool content, check whether it’s superwash treated — if it is, it can usually be machine washed cold on a gentle cycle and laid flat to dry. Non-superwash wool should be hand washed only.

If you’re gifting this blanket, it’s thoughtful to include a small card with washing instructions tucked into the ribbon or tag. New parents have enough to remember without also having to look up the care tag on a handmade item.

Finishing Touches and Gifting Ideas

A handmade baby blanket deserves a presentation that honors the work you put into it. Fold the blanket neatly into quarters and tie it with a coordinating ribbon. You can roll it into a loose tube shape and secure it with a wide satin ribbon tied in a bow, which displays the texture beautifully. If you’re also making a matching item — a hat, booties, or a small stuffed toy — you can bundle the set in a simple basket lined with tissue paper.

A handwritten card adds a personal dimension that no store-bought gift can replicate. You might simply write the name of the stitch, the year it was made, and a few words about why you chose this project for this particular baby. Decades from now, that note might be tucked inside the folded blanket when it gets pulled out of a memory box.

A Few Tips Before You Begin

The trinity stitch has a learning curve that lasts about one row. If your first ten minutes feel clumsy, push through to the end of the first row and start the second. By the third row, most crocheters find that the stitch has clicked into place and the rhythm becomes almost automatic.

Count your clusters at the end of each row until you’re confident you’re not accidentally gaining or losing stitches. It’s easy to skip the last cluster or work an extra one at the edge, especially when you’re still learning where the last stitch of a row is. Mark the final cluster with a stitch marker if that helps.

Don’t pull your yarn too tightly. The trinity stitch needs a little give to create its characteristic texture. If your clusters are compressing and the fabric feels stiff, loosen your tension slightly or move up a half hook size.

Finally, enjoy the process. A crochet project of this scale is not something you finish in an afternoon, and that’s part of what makes it meaningful. Each session you come back to it, you’re adding more rows, more color, more care. By the time you work your last stitch and fasten off, you’ll have put real hours of your time and attention into something that will be held, loved, and used. There are very few ways to give a gift quite that complete.

Final Thoughts

The Wrapped in Rainbows Trinity Stitch Baby Blanket is not a beginner project, but it’s absolutely accessible to anyone who is comfortable with basic crochet stitches and ready to try something new. The stitch is repetitive in the best way, the color possibilities are practically infinite, and the finished fabric is exactly the kind of heirloom-quality textile that makes handmade gifts worth the effort.

Whether you’re making this for your first child, a dear friend’s new arrival, or a grandchild you’ve been waiting months to meet, you’re creating something that carries meaning in every stitch. Wrap someone in rainbows. It’s one of the kindest things you can do.