Cobalt Blue Crochet Duffel Bag Pattern – Textured Bag with Zipper & Strap

There is something deeply satisfying about carrying a bag you made with your own hands. It holds your gym clothes, your weekend essentials, or your yarn stash, and every time someone asks where you got it, you get to say you made it yourself. This cobalt blue crochet duffel bag pattern is exactly that kind of project — the kind that turns heads, challenges your skills in the best possible way, and results in something genuinely functional that you will use for years.

This pattern creates a structured, textured duffel bag with a zipper closure and a sturdy shoulder strap. The cobalt blue colorway is bold and modern, making it feel less like a handmade craft and more like something you would find in a boutique. The texture comes from a combination of stitches that create a woven, almost basketweave-like surface, adding visual interest and helping the bag hold its shape over time.

Whether you are an intermediate crocheter looking for your next big project or an experienced maker wanting a practical pattern you can return to again and again, this guide will walk you through everything — materials, stitches, construction, finishing, and tips for getting the best possible result.

What Makes This Bag Special

Crochet bags have a long history, but duffel bags in particular present a fun design challenge. Unlike a flat tote or a simple drawstring pouch, a duffel needs to be cylindrical or rectangular with enough depth to hold real volume, sturdy enough to carry some weight, and finished cleanly enough to look intentional rather than homemade in the dismissive sense of the word.

The cobalt blue color choice does a lot of work here. Cobalt is vivid without being neon, rich without being dark. It photographs beautifully, making it a great option if you plan to share your finished project on social media or in a craft community. It also pairs naturally with gold, silver, white, and tan hardware, giving you flexibility when you choose your zipper and rings.

The texture in this pattern serves a dual purpose. Visually, it breaks up the large surface area of the bag and makes the finished object look more complex and intentional. Structurally, the raised stitches add a small amount of stiffness and body to the fabric, which helps the bag keep its shape when you set it down.

Materials You Will Need

Getting the right materials before you begin will save you a lot of frustration. Here is what you need for this project.

Yarn: You want a cotton-acrylic blend or a 100% cotton yarn in a worsted or bulky weight. Cotton gives the bag the stiffness and structure it needs, while a small percentage of acrylic adds stretch recovery and makes the fabric a little easier to work with. Look for a yarn labeled as craft cotton or kitchen cotton, or a blend marketed specifically for bags and accessories. For a standard duffel size (roughly 18 inches long and 9 inches in diameter), you will need approximately 800 to 1,000 yards of your main color in cobalt blue.

Hook: A size 5.0mm (H/8) or 5.5mm (I/9) crochet hook works well with most worsted cotton yarns. You want the fabric to be dense enough to hold its shape, so if your gauge is coming out too loose, drop down half a size. The goal is a firm, tight fabric rather than a drapey, soft one.

Zipper: A 16-inch or 18-inch zipper in a coordinating color. Gold metal zippers look stunning against cobalt blue and elevate the overall aesthetic considerably. You can find separating or non-separating zippers at any fabric store or online. For a duffel, a non-separating zipper is typically what you want.

Bag hardware: Two D-rings or rectangular rings and two swivel clips, all in the same metal finish as your zipper. You will use these to attach a removable shoulder strap.

Shoulder strap: You can make a crochet strap using the same yarn, or you can purchase a pre-made adjustable webbing strap in a complementary color. Nylon or cotton webbing straps are inexpensive and add a more polished, functional feel.

Lining fabric: This is optional but highly recommended. A quarter yard to a half yard of medium-weight canvas or cotton twill in a complementary color will line the interior of the bag, protect it from wear, and give it a professional finish. Navy blue, white, or a cobalt-and-white print would all look lovely.

Interfacing: If you use a lining, iron-on medium-weight interfacing will give the lining extra body and help the bag hold its cylindrical or rectangular shape.

Tapestry needle, stitch markers, scissors, and sewing thread for finishing.

Understanding the Stitch Pattern

The texture in this bag comes from alternating front post and back post double crochet stitches, which create a ribbed or woven effect depending on how you arrange them. This stitch family is called post stitches, and they work by inserting your hook around the post (the vertical bar) of the stitch below rather than into the top loops.

Front Post Double Crochet (fpdc): Yarn over, insert your hook from front to back to front around the post of the designated stitch in the row below, yarn over and pull up a loop, complete the double crochet as usual. This stitch pops forward toward you.

Back Post Double Crochet (bpdc): Yarn over, insert your hook from back to front to back around the post of the designated stitch below, yarn over and pull up a loop, complete the double crochet as usual. This stitch recedes away from you.

When you alternate fpdc and bpdc across a row, you create a ribbed fabric. When you stack fpdc stitches on top of each other for multiple rows, they create raised cables or columns. In this pattern, we use a simple alternating arrangement for the body of the bag, which creates a subtle grid-like texture that looks woven and intentional.

If you have never worked post stitches before, take twenty minutes before you start the bag to practice a small swatch. Work a foundation chain of twenty stitches, work one row of standard double crochet, and then practice alternating fpdc and bpdc across the next few rows. Once the motion feels natural, you are ready to begin.

Gauge

Gauge matters more for bags than for many other crochet projects because you want the finished dimensions to actually match what the pattern describes. Aim for roughly 14 stitches and 8 rows per four inches using a double crochet stitch with your chosen yarn and hook. Adjust your hook size as needed to match this gauge. If you are getting fewer stitches per inch, go down a hook size. If you are getting more, go up.

Construction Overview

This bag is constructed in two main pieces: the body and the base. The body is worked in the round, building upward from the base in continuous rounds. The base is a flat oval or rectangle that forms the bottom of the bag. The two end panels are added last as flat circles or rectangles, and the zipper is sewn along the top opening.

Working in the round eliminates the need for side seams and makes the bag more consistent in texture. You will use a stitch marker to track the beginning of each round.

Pattern Instructions

The Base

Begin with a foundation chain of 40 stitches. This creates the long axis of your oval base.

Round 1: Work 3 double crochet into the second chain from the hook, then work 1 dc into each chain across until the last stitch, work 3 dc into the last stitch. Rotate your work and continue working along the other side of the foundation chain, placing 1 dc into each remaining loop. Join with a slip stitch to the first dc. (You will have approximately 84 stitches.)

Round 2: Chain 3 (counts as first dc), work 2 dc into each of the next 3 stitches at the curved end, work 1 dc into each stitch along the straight side, work 2 dc into each of the next 3 stitches at the other curved end, work 1 dc across the remaining straight side. Join with slip stitch.

Round 3: Continue increasing at the curved ends by placing 2 dc into every other stitch at the curves, and working 1 dc into each stitch along the straight sides. Join.

Repeat this increase pattern for two to three more rounds until your base measures approximately 5 inches by 12 inches. You can adjust these dimensions slightly based on your intended bag size.

The Body

Once the base is the size you want, stop increasing and begin working straight rounds. From this point forward, work 1 fpdc into every stitch that was a fpdc in the previous round, and 1 bpdc into every stitch that was a bpdc. For the first round transitioning from the base, work all stitches as dc to establish your column, then begin alternating on the next round.

To begin the textured body:

Round 1 (texture establishment): Work fpdc into first stitch, bpdc into next stitch, alternating across the entire round. Join.

Round 2 and all subsequent rounds: Work fpdc over fpdc (meaning into the same post stitch that was a fpdc last round), and bpdc over bpdc. This stacks the raised and recessed stitches into vertical columns.

Continue working in this pattern until the body measures approximately 11 to 12 inches tall. This is the height of your duffel before the zipper is added.

The End Panels

Work two flat ovals following the same increase pattern as the base, but stop after three or four rounds so they are slightly smaller than the base. These will be sewn to the two short ends of the bag body.

Alternatively, if you prefer a cleaner look, you can work the end panels continuously as part of the body by working in the round from the bottom up and shaping the ends. This requires more advanced shaping and is best attempted by makers who are comfortable with three-dimensional crochet construction.

Attaching the Zipper

The zipper goes along the top opening of the bag. Before sewing, pin it in place and check that it lies flat without puckering. Use a tapestry needle and matching thread, or a sewing machine if you are comfortable doing so, to sew the zipper tape to the inside of the top opening using a whip stitch or backstitch. Work slowly, keeping your stitches even and pulling gently so the zipper does not distort the crochet fabric.

Once the zipper is in, zip it closed and check that the opening closes cleanly. Tug gently to confirm it is secure before moving on to the lining.

Adding the Lining

Cut your lining fabric to match the interior dimensions of the bag, adding a half inch seam allowance on all sides. Apply interfacing to the wrong side of the lining fabric according to the package instructions. Sew the lining pieces together, press the seams, and slip the lining into the bag wrong side out. Fold the raw top edge of the lining under by a half inch and pin it to the inside of the zipper tape. Hand sew the lining in place using small, even stitches. The lining should sit smoothly inside the bag without pulling or bunching.

Making the Strap

If you are making a crochet strap, work a foundation chain long enough to reach from hip to shoulder when doubled, approximately 40 to 50 inches. Work rows of slip stitch or single crochet back and forth until the strap is about one inch wide. Finish with a row of slip stitch along all edges to clean it up.

Attach one swivel clip to each end of the strap using a small loop of yarn or a small piece of webbing stitched into a loop. Sew or rivet D-rings to each short end of the bag at the seam between the body and the end panel. Clip the strap onto the D-rings and you are done.

If you purchased a pre-made strap, attach it the same way using the included hardware.

Finishing Touches

Weave in all your ends carefully using a tapestry needle, burying the tails inside the fabric to hide them. If the bag has any stiffness that feels awkward, lightly block it by spraying with water and reshaping it to the dimensions you want, then letting it dry flat.

Consider adding a small crochet zipper pull in a contrasting color, a tassel, or a charm to the zipper tab for a personalized touch. A simple tassel made from the same cobalt yarn adds a fun detail without much extra effort.

Tips for Success

Use stitch markers liberally. In a long round of post stitches, it is easy to lose your place, and a misplaced stitch can throw off the entire column of texture. Markers placed every twenty stitches make it easy to catch mistakes early.

Work tightly and consistently. The texture in this bag only looks crisp if the tension is even. If you find your tension wandering, take a break and come back fresh.

If the cobalt blue color you love is not available in your preferred yarn, remember that you can have yarn dyed or you can look for “peacock,” “electric blue,” or “sapphire” colorways, which are often in the same family.

Test your zipper before committing. Buy your zipper and set it against your swatch to confirm the color and finish work together before you are halfway through the project.

Caring for Your Finished Bag

Cotton and cotton-blend yarns are generally machine washable, but check the label on your specific yarn to confirm. When washing your finished bag, place it in a mesh laundry bag to protect the hardware and prevent the zipper from snagging. Wash on a gentle cycle in cold water and lay flat to dry. Do not put it in a dryer, as heat can warp the shape and cause the yarn to shrink unevenly.

If the bag gets a spot or stain, spot-cleaning with a damp cloth and mild soap is usually sufficient and much gentler on the fabric than a full wash.

Why Crochet Bags Are Worth Making

Store-bought bags are made to a price point. They use the least expensive materials that will hold together long enough to survive the return window, and they often feel cheap, look generic, and fall apart at the seams within a year or two. A handmade bag is the opposite of that. You choose the materials, you control the construction, and you end up with something that reflects your taste and skill.

A cobalt blue crochet duffel bag is also a genuinely impressive gift. It works for gym-goers, travelers, yoga practitioners, students, or anyone who appreciates both beauty and function. Because it takes real time and skill to make, it communicates care and intention in a way that almost nothing purchased can.

And perhaps most importantly, making it is satisfying in a way that is hard to describe to someone who has not experienced it. There is a particular pleasure in watching a flat strand of yarn become, through repetitive and meditative motion, something three-dimensional and useful. By the time you finish this bag, you will have worked thousands of stitches, and every one of them will show in the finished object — in its texture, its structure, its weight in your hands.

Pick up your hook, wind your cobalt yarn, and get started. The bag is waiting to be made.