On a computerized sewing machine, the features you will use on every garment are the needle up/down setting, the speed slider, the one-step buttonhole and, if the machine has one, the automatic thread cutter. Stitch memory, the start/stop button, a tie-off key, mirror imaging and twin-needle mode earn their place a few times a month. The 200 decorative stitches and the alphabet that fill the brochure are what you will use least. Pay for the first group, be glad of the second, and do not pay extra for the third.
| Feature | What it does | How often a garment sewist uses it |
|---|---|---|
| Needle up/down | Stops with the needle in or out of the fabric, every time | Every seam |
| Speed slider | Caps the top speed regardless of pedal pressure | Every project |
| One-step buttonhole | Sews a buttonhole sized to the button in one pass, repeatable | Every shirt, skirt and waistband |
| Automatic thread cutter | Cuts both threads at a button press | Every seam, once you have it |
| Direct stitch selection | Stitch chosen by number or screen, with length and width preset | Every project |
| Start/stop button | Sews without the pedal | Long seams, topstitching, people with knee trouble |
| Stitch memory | Saves your length, width and tension for a stitch | A few times a month |
| Tie-off or locking stitch | Secures the start and end without backstitching | Topstitching, darts, decorative work |
| Mirror and elongation | Flips or stretches a stitch pattern | Rarely for garments |
| Twin-needle mode | Limits the width so a twin needle clears the plate | Knit hems |
| Thread and bobbin sensors | Warns when the top thread breaks or the bobbin runs out | Helpful, not essential |
| 100 to 300 decorative stitches | Patterns, satin stitches, alphabets | A handful, rarely |
What makes a sewing machine computerized?
In a mechanical machine, dials move the needle bar sideways and set the feed through cams and levers, and the stitch is whatever those parts produce at that moment. In a computerized machine, stepper motors move the needle bar and the feed dogs under the control of a circuit board that stores every stitch as numbers. The board also knows where the needle is, which is what makes needle up/down, the thread cutter and the sensor buttonhole possible. The main motor is usually electronically controlled too, so it keeps its force at low speed, which matters for thick seams in denim and canvas. Mechanical vs computerized sewing machine weighs the two approaches; this post looks inside the computerized one.
Which features will you use on every project?
Needle up/down. Set to down, the needle stops in the fabric when you lift your foot, so you can pivot at a corner, turn a curve or lift the presser foot to adjust without the fabric shifting. Set to up, it stops clear of the fabric for removing the work. It sounds minor until you topstitch a collar or sew around a pocket; how to topstitch straight relies on it.
The speed slider. The pedal still controls the speed, but the slider sets the ceiling. Beginners set it low and sew with the pedal floored, which gives an even speed and straighter seams. Experienced sewists set it low for curves, buttonholes and sheers, and high for long straight seams.
The one-step buttonhole. A sensor foot holds the button, the machine measures it and sews the whole buttonhole, both sides and both bar tacks, without you turning a dial between steps. More important than the convenience is the repeatability: the seventh buttonhole on a button-front top is the same length as the first. Mechanical machines sew buttonholes in four steps, which works but takes care. How to sew buttonholes covers both.
The automatic thread cutter. A button cuts both threads under the plate and leaves tails ready for the next seam. It removes a snip and a reach after every seam, which over a garment is a few hundred of them. Whether it is worth paying for on its own is the question of automatic thread cutter and knee lift: are they worth it?; in short, you will not want to go back.
Direct stitch selection with presets. Press 01 for a straight stitch and the machine sets a 2.5 mm (3/32 in) length and the center needle position; press the zigzag and it sets a sensible width. Most machines show which presser foot to use. You will still change the presets, but you start from a reasonable place every time, and the stitch you chose is the one you get, with no dial landing between two.
Which features are nice to have?
Stitch memory. Save your blind hem at 2 mm length and 3 mm width, or your knit stitch for a particular jersey, and recall it next time. It becomes useful once you sew the same fabrics repeatedly.
A tie-off key. Sews a few stitches in place at the start or end, which is neater than backstitching on topstitching and darts and does not thicken the seam.
Start/stop button and pedal-free sewing. Useful for long seams, for people with knee or hip trouble, and for steady topstitching at a fixed speed. Many people try it and go back to the pedal; some never use the pedal again.
Needle positions. Computerized machines offer many positions, which is handy for edgestitching and zip insertion with a standard foot. Some mechanical machines offer left, center and right, which is enough for most of this.
Twin-needle mode and width limits. The machine caps the zigzag width so a twin needle cannot hit the plate. If you hem knits with a twin needle, this saves broken needles; see hemming knits: twin needle vs coverstitch vs zigzag.
Adjustable presser foot pressure, a knee lift and an automatic presser foot lift. These are not computerized functions as such, but they tend to appear on the same mid-range and upper machines. Presser foot pressure is the one to look for: it decides whether the machine feeds a fine lawn and a thick fleece equally well.
Which features will you rarely use for garments?
The decorative library. A garment uses the straight stitch, the zigzag, a stretch stitch or two, the blind hem, an overcasting stitch and a buttonhole; which sewing machine stitches do you actually need? lists them. Of a library of 200, perhaps ten are worth the space, and the rest are for quilting, children's clothes, linens and embellishment. If that is your sewing, they are a reason to buy; if it is not, a machine with 30 stitches that feeds well is a better machine than one with 300 that does not.
The same goes for alphabets, built-in tutorials on a color touchscreen, stitch creators and projector overlays on high-end models. Most garment sewists discover them a year after buying the machine.
What do you give up with a computerized machine?
Repairs cost more, because a circuit board is replaced rather than adjusted, and after 15 to 20 years boards for a discontinued model may not exist, while a mechanical machine can be serviced indefinitely. Computerized machines do not like voltage spikes, so a surge protector is a cheap precaution. And the stitch width ceiling is set by the machine, not by you: a 5 mm (3/16 in) machine stays a 5 mm machine, while 7 mm (1/4 in) and 9 mm (3/8 in) models cost more.
In return you get stitch quality that does not depend on how you turn a dial, full needle penetration at slow speed, and the three or four features above that mechanical machines cannot offer. For most people sewing clothes, that is a fair trade.
Which features should you pay for?
A beginner buying one machine should have needle up/down, a speed slider, a one-step buttonhole, a needle threader and adjustable presser foot pressure. Those five cover every pattern in a first year, and a pattern's sewing guide, Sewly's included, lists the buttons and zip so you know which buttonhole and foot you will need before you start. Decorative stitches do not matter at this stage.
A garment sewist upgrading should add the automatic thread cutter, stitch memory, a knee lift and a tie-off key, and look at the maximum stitch width if twin-needle hems and wide zigzags are part of their sewing.
Someone who also quilts or embellishes is the one buyer for whom a large stitch library, alphabets and a wide throat are worth real money.
On a tight budget, a good mechanical machine with a four-step buttonhole and strong feed beats a cheap computerized machine with a weak feed and 100 stitches. The electronics are only an advantage when they sit on a machine that sews well without them.