The Cardigan vs the Pullover: Key Differences
If you can knit a pullover sweater, you can knit a cardigan. The skills are identical — the construction has a few additional elements that are worth understanding before you start. Specifically: the open front (which creates two separate front pieces instead of one), the button band (a strip of ribbing picked up along the finished fronts), and the buttonholes (worked into that band). Everything else — sleeves, back, shoulder shaping, neckline — is the same as a pullover.
The key differences to understand before casting on:
- A cardigan has two front pieces instead of one front piece
- The neckline shaping is different on each front — it mirrors across the centre front
- A button band is added after the body is complete (or sometimes worked simultaneously)
- Cardigans can be worked flat throughout (even in seamless constructions, the front opening means you're working back-and-forth for much of the body)
Construction Method 1: Worked in Pieces and Seamed
The traditional construction: you knit five separate pieces (back, left front, right front, left sleeve, right sleeve), then seam them together using mattress stitch or three-needle bind-off.
The Back
Identical to a pullover back. Cast on, work the body, shape the armholes, shape the shoulders and neck, bind off.
The Two Fronts
Each front is approximately half the width of the back, minus a few stitches (the fronts overlap slightly at the centre for the button band). The fronts are mirror images of each other — one has left-leaning shaping, the other has right-leaning shaping. Patterns usually write out one front in full and then say "work as for right front, reversing shaping" for the other.
What "reversing shaping" actually means: if the right front decreases at the beginning of right-side rows, the left front decreases at the beginning of wrong-side rows (which is the same physical location — the front edge — but reached on different rows). A decrease that was k2tog becomes ssk, and a decrease worked at the start of a row becomes one worked at the end. The logic is about which edge of the garment you're shaping.
If "reversing shaping" confuses you, try this: work the right front, then before starting the left front, read through the right front instructions row by row and swap every "right side" to "wrong side" and vice versa. Write out your revised instructions. Then follow those.
Seaming
Mattress stitch is the standard for side seams and sleeve seams — it creates an invisible join when worked correctly. Set-in sleeves are typically joined using backstitch for a firmer seam. Take your time with seaming; a rushed seam can ruin an otherwise beautiful garment.
Construction Method 2: Seamless
Modern knitters increasingly prefer seamless cardigans — worked in one piece from the bottom up or top down, with the armholes created by separating body and sleeves onto waste yarn. The result has no seams, no sewing, and can be tried on as you go.
Bottom-Up Seamless
Cast on all front and back stitches together on a long circular needle. Work the body flat (because of the open front) until you reach the armhole. Separate the front, back, and sleeve stitches. Work the back in the round. Work the fronts flat. Work the sleeves in the round. Pick up sleeve stitches from waste yarn and join.
Top-Down Seamless
Begin at the neck, work increases down through the yoke, separate sleeves, work body and sleeves downward. This construction makes fitting the yoke very easy — try it on after every 10 rounds and adjust as needed.
The Steek
Some seamless cardigans use a steek — a column of extra stitches at the centre front that allows the garment to be worked entirely in the round (as a closed tube), then cut open after completion. The cut edges are secured before cutting, usually with machine stitching or hand-sewn reinforcement. Steeking is more advanced but produces an exceptionally tidy result and works especially well for colourwork cardigans.
The Button Band
The button band (also called a button band and buttonhole band) is worked after the body and sleeves are complete. It's a strip of ribbing (usually k1, p1 or k2, p2) picked up along the front edges of the cardigan.
Picking Up Stitches for the Band
The general rule for picking up along a vertical edge in stockinette: pick up 3 stitches for every 4 rows. This ratio prevents the band from puckering (too many stitches) or pulling in (too few). In garter stitch, pick up 1 stitch per ridge.
Use a crochet hook to pick up stitches if you find the needle awkward. Pick up through both legs of the edge stitch for the neatest result.
Spacing the Buttonholes
Before working the band, decide how many buttons you want and mark their positions with stitch markers or removable markers. The top button usually sits 1–2cm below the neckline; the bottom button sits 1–2cm above the hem. Remaining buttons are spaced evenly between.
Work the band in ribbing for 3–5 rows (half the total band depth). On the next row, create buttonholes at each marked position. The simplest buttonhole: k2tog, yo (for small buttons) or bind off 3 stitches and cast on 3 in the following row (for larger buttons). Work the remaining band rows in ribbing, then bind off in pattern.
Choosing Your Construction
If you're new to cardigans:
- Work in pieces if you prefer flat knitting, want to follow a traditional pattern exactly, or are making a fitted garment where precise seaming helps the construction hold its shape
- Work seamlessly if you enjoy circular knitting, want to minimise finishing work, and like the ability to try on the garment as you knit
Either construction produces the same result. The seamed version involves more finishing; the seamless version involves more planning. Both are equally valid choices from an expert's perspective.