Choosing buttons for knitwear and cardigans follows different rules from choosing them for woven garments. Knitted fabric stretches, it's looser and lighter, the buttonhole is knitted rather than cut, and the button is often sewn on with yarn instead of thread. Pick a button by eye and you risk a sagging cardigan front, a stretched buttonhole or a button that tears out along with the stitches. Here's how to get it right, step by step, plus answers to the questions knitters ask most.
Step 1: Choose the button before you knit the buttonholes
This is the single most important tip. With knitting, the buttonhole is made to fit the button, not the other way round. Buy your buttons, knit a swatch of the band with one or two buttonholes and test. You'll know exactly how many stitches to leave, and you won't be hunting for a button to fit holes that are already knitted.
Step 2: Size to the yarn
| Yarn weight | Typical garment | Button size |
|---|---|---|
| Fine (2 to 3 mm needles) | Baby cardigan, fine top | 10 to 15 mm |
| Medium (3.5 to 5 mm needles) | Classic cardigan | 15 to 22 mm |
| Chunky (6 to 8 mm needles) | Thick cardigan, knitted jacket | 22 to 28 mm |
| Super chunky (9 mm+ needles) | Knitted coat, oversized cardigan | 28 to 34 mm |
The button should be slightly larger than the knitted buttonhole at rest. The knit will stretch to let it through but won't let it slip out on its own.
Step 3: Go for a lightweight material
Heavy buttons drag a loose knit downward, so the front sags and loses shape. That's why lightweight materials are preferred on knitwear:
- Wood: the lightest option, warm and well suited to wool and cotton. See our wooden buttons from 15 to 28 mm.
- Coconut: light, strong and naturally patterned, ideal for rustic and Scandi-style pieces. Browse our coconut buttons.
- Corozo: yarn retailers in Bulgaria often recommend it for women's, baby and children's knits. It's hard without being heavy and comes in many colours. See our corozo buttons.
- Leather football buttons: a classic on men's cardigans and Aran sweaters. For a similar look without leather, try dark wood or textured coconut.
- Metal: use sparingly, and only on dense, tight knits.
Step 4: Holes or shank
If you're sewing on with yarn, the holes need to be wide enough, otherwise the yarn frays as you pull it through. With small holes, use split yarn (a single ply of your yarn) or a strong matching sewing thread. Shank buttons are an excellent choice for chunky knits: the shank lifts the button above the thick band, making it easy to fasten.
Step 5: Reinforce the band
- Backing button. Sew a small flat button (10 to 12 mm) on the inside at the same time as the main button. It spreads the load and stops the button pulling stitches out.
- Tape behind the band. Stitch grosgrain or cotton tape to the inside of the button band; on the buttonhole band, slit the tape exactly under each buttonhole and finish the edges. The band then can't stretch. Have a look at our ribbons and tapes.
- Thread shank. Even with flat buttons, leave a 3 to 5 mm shank, matching the thickness of the knitted band.
Tip: lay the buttons out on the cardigan before sewing and try it on. Spacing of 6 to 8 cm is typical, though chunky knits can take more; what matters is that the band doesn't gape between buttons.
Knitted buttonhole types and which button fits
Different buttonholes hold differently, and that affects your button choice:
- Yarn-over eyelet. The smallest and simplest, right for small 10 to 13 mm buttons on baby cardigans. With a bigger button it stretches out of shape.
- Horizontal buttonhole over 2 to 4 stitches. The all-rounder for classic cardigans. The stitch count comes from your swatch; the hole is usually about two-thirds of the button diameter when relaxed.
- One-row buttonhole. Firm with a neat edge, good for larger buttons and garments that get buttoned often.
- Vertical buttonhole. Used less often, on narrow bands or decorative styles. Suits elongated or oval buttons.
Whichever you choose, reinforce the edge with buttonhole stitch or whip stitch if the yarn is slippery, so it doesn't stretch after a few wears.
Common problems and fixes
- The front sags: buttons are too heavy or the band isn't reinforced. Switch to wood or coconut and add tape behind.
- The button keeps coming undone: the buttonhole has stretched. Tighten it with a few yarn stitches at the end, or choose a larger button.
- The button pulls the stitches: there's no backing button. Add one.
- The colour doesn't work: natural buttons in beige, brown and grey suit almost any heathered or undyed yarn.
Caring for knitwear with buttons
Knits are usually hand-washed or machine-washed on a delicate cycle at up to 30 °C, conditions natural buttons handle well. Dry the cardigan flat so the band doesn't stretch under the weight of wet knit and buttons. If the buttons are wooden, don't leave the garment soaking for long.
FAQ
How many buttons should a cardigan have?
Usually 5 to 7 for a classic length, with the top one 1 to 1.5 cm below the neckline and the bottom one about 8 to 10 cm from the hem.
Are shell buttons suitable for knitwear?
Yes, on fine cotton or silk knits for baby and women's cardigans. On chunky wool, shell can look too delicate.
Should I sew buttons on with yarn or thread?
If the holes allow, use split yarn in a matching colour; it's less visible. With small holes, a strong polyester thread is the better choice.
Bul-tex manufactures and supplies natural buttons and takes custom orders from knitwear brands. Get in touch through the contact page.
