Working with Denim
Denim. It's iconic, dependable, rugged, and often misunderstood. From crisp raw selvedge jeans to soft chambray shirtdresses, denim is a cornerstone of fashion. Yet, for all its popularity, denim can be intimidating for some. Its weight, structure, and tendency to fray can challenge beginners, and even seasoned sewists. However, with the right techniques, tools, and knowledge, denim can be one of the most satisfying materials to work with. Here’s everything you need to know to sew denim garments that look and feel professionally made.
Denim is a woven fabric typically made with a twill weave—diagonal ribs that give it strength and subtle stretch. It comes in a range of weights and finishes, each suitable for different projects:
Lightweight Denim (4–6 oz):
Soft and drapey, this denim is ideal for shirts, blouses, dresses, and lightweight trousers. It handles similarly to quilting cotton and is great for beginners.
Midweight Denim (7–10 oz):
Perfect for everyday jeans, jumpsuits, skirts, and jackets. This is the most versatile denim and behaves well with proper tools.
Heavyweight Denim (11–16 oz+):
This is workwear territory. Think raw jeans, outerwear, and structured bags. It requires stronger machines and more patience, but the payoff is durability and structure.
Specialty Denims:
Stretch Denim: Contains spandex (elastane), ideal for skinny jeans and body-con styles.
Selvedge Denim: Woven on shuttle looms with self-finished edges. Often used in raw, unwashed form.
Chambray: Not technically denim, but a close cousin with a similar look and lighter weight. Great for shirts.
Prep
Prewash Your Fabric:
Denim shrinks, bleeds dye, and relaxes after washing. Always prewash your yardage in cold water, dry it, and iron it flat before cutting. You can serge or zigzag the raw edges beforehand to minimize fraying in the wash.
Mark Smart:
Personally, I usually mark most heavy fabrics with a regular writing pen for precision, and because I’m in the habit of only marking on the wrong side. But I recommend using chalk wheels or tailor’s wax because these markings stay visible on textured denim. Some “disappearing” pens don’t fully come off denim, and other types of marking may stain or wipe off completely while working. Always use a scrap piece of fabric to test your markings and other things such as ironing, washing off, etc. to see how it affects your fabric. Understanding Denim: Types & WeightsTools: Sewing Denim with Ease
Denim can be unforgiving if you're unprepared. But with a few simple swaps, your machine and your sanity will thank you.
Needle:
Use denim needles—they're stronger and sharper than universal needles, with a reinforced shaft designed to penetrate multiple layers.
size 90/14 for midweight
size 100/16 or 110/18 for heavyweight
Replace needles every 6–8 hours of sewing, or sooner if you hear popping sounds or notice skipped stitches. To make things easy, I swap my needle after each project.
Thread:
Investing in quality thread is important for all your sewing, but especially when working with materials like denim. For sewing, opt for a heavy-duty polyester thread (or cotton-wrapped polyester); these types of thread are durable and resistant to fraying.
Also, top-stitching denim isn’t just decorative, it’s functional. Top stitching will reinforce the seems and enhance a garments durability. Top-stitching thread is thicker and stronger than regular all-purpose thread, making it ideal for visible stitches that stand out and need to hold up over time. It will also give finished pieces a professional polish. For topstitching, use topstitch thread only in the needle, with regular thread in the bobbin, and adjust tension accordingly (try 3.0–4.0 mm).
Cutting and Holding:
When cutting, use sharp fabric shears or a rotary cutter with a fresh blade. Instead of pinning, try fabric clips—they work better on thick seams and won’t distort layers. I hardly ever use pins because fabric clips are more secure and don’t slip.
Sewing Techniques for Strong, Stylish Garments
Press As You Go:
For best results, press your seams open or to one side, depending on the style.
Use a tailor’s clapper to flatten thick seams. Bulky denim seams can also be hammered down (yes, with a regular hammer!)
Topstitch pressed seams immediately to hold them in place.
Stitch Settings:
Use a longer stitch length (3.0–3.5 mm) for seams and topstitching to optimize flexibility. The length will vary based on the type of denim used, but often a regular stitch is too tight to accommodate the thickness of working with heavier layers. It will also help prevent puckering.
For stress points (like crotch seams or underarm areas), use bar tacks or sew twice for additional reinforcement.
Avoid backstitching with topstitch thread; instead, leave tails and pull them through to knot by hand.
Denim is not a fabric you conquer, it’s one you collaborate with. It rewards patience and punishes shortcuts. Understanding your denim—its weight, grain, and character, is the key to making something beautiful.
