How to Make a Scrap Yarn Bag | DIY Knit Swatch Bag Tutorial
If you’ve been knitting for more than a season, you already know the struggle. Yarn scraps pile up in corners, spill out of bins, and somehow multiply when you’re not looking. Those leftover bits from finished sweaters, the single skein you bought on a whim, the partial balls from swatching — they’re too good to throw away but not quite enough to start a new project with. That’s where a scrap yarn bag comes in, and more specifically, the knit swatch bag that uses those exact scraps to create something beautiful, functional, and deeply satisfying to make.
This tutorial walks you through the entire process of making a DIY knit swatch bag from start to finish. Whether you’re a beginner looking for a forgiving first project or an experienced knitter wanting to clear out your stash, this is one of those projects that feels like it was designed specifically for people who love yarn a little too much.
What Is a Scrap Yarn Bag?
A scrap yarn bag is exactly what it sounds like — a bag knitted from leftover yarn scraps. But unlike some stash-busting projects that feel like a compromise, a well-made scrap yarn bag is a genuine showpiece. The beauty of this style of bag is that the randomness of the colors and textures is the point. You’re not trying to match. You’re celebrating the variety.
The particular style this tutorial focuses on is a swatch bag, which gets its name from the patchwork-like quality of the finished fabric. When you knit with many different yarns — switching colors, weights, and even fiber types — the resulting fabric has a textural richness that no single yarn could produce. Think of it like a textile version of a quilt: humble materials, combined with intention, producing something greater than the sum of its parts.
These bags are also highly practical. They’re sturdy enough to use as a project bag, a market tote, a gift bag, or even an everyday purse. The thick, varied fabric holds its shape well, especially if you full or block the finished piece.
Materials You’ll Need
Before you cast on, gather everything you need. One of the best things about this project is that the materials list is wonderfully flexible.
Yarn: This is where you use your scraps. Aim to collect yarn in a similar weight range — a mix of DK, worsted, and aran weight tends to work well together. Avoid combining very fine laceweight with very bulky yarn in the same bag, as the difference in fabric density can be hard to manage. You’ll need roughly 200 to 400 yards total, depending on the size of bag you want to make. Don’t worry about having full skeins. Short lengths of a few yards are perfect here.
Needles: Choose a needle size appropriate to your dominant yarn weight. For a worsted-weight-centered project, US size 7 or 8 (4.5mm or 5mm) needles work well. You can use straight needles if you plan to seam the bag, or circular needles if you want to knit it in the round.
Tapestry needle: You’ll need this for weaving in ends, and there will be many ends. Embrace this part of the process. Each end woven in represents a story — a project you finished, a yarn you loved.
Scissors: A small, sharp pair kept nearby while you work.
Stitch markers: Optional, but helpful for marking pattern repeats or the beginning of a round.
Handles or straps: You can knit an i-cord handle, braid yarn for a strap, purchase leather or wooden bag handles, or repurpose handles from an old bag. This is a decision you can make at the end based on how the bag turns out.
Optional lining fabric: A simple cotton lining inside the finished bag will prevent small items from slipping through the stitches and gives the whole thing a more polished look.
Choosing and Preparing Your Scraps
Spend a few minutes before you start sorting your scraps by weight and doing a rough color audit. You don’t need to be overly precise — part of the charm of this project is improvisation — but having a general sense of what you’re working with helps you plan the overall look.
If you want a more cohesive color story, organize your scraps into warm tones, cool tones, or neutrals and pull from one family. If you love a maximalist, kaleidoscopic result, pull scraps at random and let the bag surprise you.
Wind very short scraps into small butterflies or wrap them loosely around a piece of cardboard so they’re easy to pick up and work with. Tangles mid-project slow everything down and drain the joy from the process.
Check your scraps for any damaged fibers — yarn that’s become brittle, badly felted, or weakened from storage. These pieces won’t knit up well and can weaken the finished bag. Set them aside for other uses like stuffing or surface decoration.
The Basic Pattern: Step by Step
This pattern is written for a medium-sized bag, approximately 12 inches wide and 10 inches tall before seaming. You can easily scale it up or down by adjusting the number of stitches you cast on.
Gauge
Because you’re working with mixed yarns, a precise gauge isn’t critical here. Aim for a fabric that’s firm and dense — you want the bag to hold its shape. If your knitting feels loose and drapey, go down a needle size. Approximately 18 stitches and 24 rows to 4 inches in stockinette with a worsted weight yarn is a good target to aim for, but don’t stress if you’re slightly off.
Casting On
Using your first scrap yarn, cast on 54 stitches. A long-tail cast on gives a clean, elastic edge, but any cast on you’re comfortable with will work. If you want to knit the bag in the round and avoid seaming, cast on 108 stitches and join to work in the round, being careful not to twist.
The Knit Swatch Texture
The texture of this bag comes from combining different stitches and yarns freely. Here is a simple structure to follow, but treat it as a guideline rather than a strict rule.
Work 4 to 6 rows in your first yarn using stockinette stitch (knit on the right side, purl on the wrong side). When that yarn runs out or when you want a change, join your next scrap yarn and work 4 to 6 rows in a different stitch pattern. Rotate through any of the following stitch patterns as the mood strikes you.
Garter stitch (knit every row) creates a firm, ridged texture and lies flat — ideal for scraps that are a little finer than the rest, as the extra rows build up the fabric weight nicely.
Seed stitch (alternate knit and purl stitches across the row, reversing on every row) creates a bumpy, woven-looking fabric and is beautiful in contrast with stretches of stockinette.
Moss stitch (knit two, purl two for two rows, then reverse for two rows) creates a slightly different texture than seed stitch and works well in mid-length stretches.
Rib stitch (knit two, purl two, repeated to end of row) adds elasticity and a structured look. This is particularly nice near the top of the bag where you want the opening to have a little grip.
As you work through your scraps, don’t worry about transitions being perfect. A row of bumpy garter between two smooth stockinette sections can look like a deliberate design choice — because it is.
Changing Colors and Joining New Yarn
When you’re ready to switch to a new scrap, you have a few options. The simplest is to just tie the new yarn to the old one with a loose knot at the edge of the work, leave a 6-inch tail on each end, and continue knitting. You can weave in the tails and undo the knot later, or leave the knot and simply weave the tails neatly into the edge.
If you want a cleaner join, try the Russian join or the spit-splice (which works for non-superwash wool). These methods create an invisible join with no tail to weave in, which is a genuine gift on a project with this many yarn changes.
Don’t be afraid to use very short lengths of yarn. Even 3 to 4 yards can create a satisfying stripe before you move to the next color. Some of the most beautiful scrap knitting uses lengths that other knitters would throw away.
How Long to Knit
Continue in this manner until your piece measures approximately 21 to 22 inches long (if knitting flat). This will fold in half to create a bag roughly 10 to 11 inches tall. If knitting in the round, work until the tube measures 10 to 11 inches from the cast-on edge.
Finishing the Bag
Binding Off
When you reach your desired length, bind off loosely using the same needle size or one size larger. A tight bind-off at the top of the bag will make the opening stiff and difficult to use, so err on the side of loose here.
Seaming (Flat Method)
If you knit flat, fold the piece in half widthwise so the right sides face each other. Using your tapestry needle and a length of sturdy yarn, seam along the bottom edge and up one side using mattress stitch or whip stitch. Turn the bag right side out.
If you knit in the round, your bag is already a tube. Simply seam or sew across the bottom edge.
Weaving In Ends
Now for the meditative part. Weave in every tail end securely, at least 2 to 3 inches in two different directions. With mixed fibers, ends can work loose more easily than in single-yarn projects, so be thorough. Use your tapestry needle to run each tail through the backs of several stitches, reverse direction, and trim close to the fabric.
Adding Handles and Straps
The handle you choose will significantly influence the final look and function of the bag. Here are a few options.
Knitted i-cord: Cast on 4 stitches and knit an i-cord to your desired strap length (typically 18 to 24 inches for a shoulder bag, or 10 to 12 inches for a short handle). An i-cord is made by knitting 4 stitches, then sliding them back to the left needle without turning the work, and pulling the working yarn across the back before knitting again. Repeat until the cord is the right length. Sew both ends securely inside the top of the bag.
Braided yarn strap: Gather 12 to 18 long lengths of your scrap yarn and divide them into three equal groups. Braid tightly to the desired length and tie or sew the ends. This creates a thick, colorful rope handle.
Purchased handles: Leather bag handles with pre-drilled holes can be attached by threading yarn through the holes and into the bag. This instantly elevates the look of the finished piece and makes it feel more polished and intentional.
No handles at all: A simple open-top bag with no handles works beautifully as a project bag, a gift bag, or a decorative storage basket.
Optional: Lining the Bag
Lining a knit bag is a step that takes maybe 20 to 30 minutes and makes a significant difference in durability and usability. Choose a sturdy woven cotton fabric — canvas, denim, or even a quilting cotton.
Cut two rectangles slightly smaller than the finished bag dimensions, adding a half-inch seam allowance on all sides. Sew them together along the bottom and both side seams. Fold the top edge down by a half inch and press it flat. Slip the lining inside the bag, align the folded top edge just below the bag’s opening, and hand sew it in place using a whip stitch or slip stitch.
A lined bag holds its shape better, is easier to use, and gives the impression that you spent far more effort on it than you did.
Tips for Making the Most of This Project
Use this project as a way to track your knitting history. If you label your scraps with the project they came from, you can knit a bag that’s literally made of memories — a stripe from that first sweater, a few yards from the socks you made your mom, some leftover from the blanket that took two years to finish.
Don’t overthink the color combinations. Some of the best color work in knitting happens accidentally, and the scrap bag format is forgiving of almost any combination. If two colors feel jarring next to each other, add a row of neutral beige or grey between them to act as a visual buffer.
If you run out of a particular color mid-stripe and want more of that texture, improvise. Use a different yarn but switch to a pattern stitch that creates a similar visual weight. The overall effect will be cohesive even if the materials aren’t identical.
Consider making multiple small bags rather than one large one. A set of three scrap yarn bags in graduating sizes makes a beautiful gift and lets you use even the shortest scraps in the smallest bag.
Why Scrap Yarn Knitting Matters
There’s something philosophically satisfying about scrap yarn knitting that goes beyond the practical stash-busting benefit. When you knit a bag from leftover yarn, you’re practicing a kind of material honesty — you’re using what you have rather than chasing the perfect new thing. In a world of relentless consumption, that’s a quietly radical act.
It also teaches you to work with constraints. When you can’t choose your ideal yarn for every section, you have to make creative decisions with whatever’s available. This kind of improvisation, practiced regularly, makes you a more flexible and imaginative knitter overall.
And there’s the simple pleasure of completion. Finishing a project that uses up scraps means two things are done at once: the bag exists, and the scraps are gone. The double satisfaction of that is hard to beat.
Final Thoughts
A scrap yarn bag is the kind of project that rewards you in proportion to how much you relax into it. The more you let go of the need for everything to match perfectly, the more fun and beautiful the process becomes. Your bag will be completely one of a kind — not because you planned it that way, but because your specific pile of scraps, worked by your specific hands, in your specific sequence of decisions, could never be replicated exactly.
That’s the real gift of making something like this. Not just the finished bag sitting on your shelf looking cheerful and useful, but the reminder that making things with your hands — even simple things, even imperfect things, even things made from the leftover bits of other things — is always worth doing.
So pull out that yarn scrap bin, pick up your needles, and start knitting. Your bag is already in there, waiting to be found one stripe at a time.
