Rotary cutter vs scissors for cutting fabric

A rotary cutter is faster and more accurate than scissors on long straight edges, gentle curves, slippery fabrics and anything cut in several layers, because the fabric lies flat on the mat while the blade rolls through it. Scissors win on tight curves, notches, small pieces, thick or bulky cloth and any time there is no mat under the fabric. Most people who sew clothes end up with both: a 45 mm (1 3/4 in) rotary cutter with a self-healing mat for the main pieces, and a pair of 20 to 25 cm (8 to 10 in) dressmaking shears for everything else.

How does a rotary cutter cut fabric differently from scissors?

Scissors cut by shearing: the lower blade slides under the fabric and lifts it a little with every stroke, so the fabric moves while you cut. On a stable cotton that hardly matters. On a viscose challis or a silk, every lift shifts the cloth against the pattern, and the piece you end up with is a few millimeters different from the piece you meant to cut.

A rotary cutter is a circular blade on a handle, like a pizza wheel. You press it down and roll it along the edge of the pattern, and the fabric stays pressed against the cutting mat the whole time. Nothing lifts, nothing shifts, and the cut edge is as clean as the blade. The price is that you need the mat under everything you cut, a sharp blade, and somewhere to put a table large enough for a skirt panel.

When is a rotary cutter better?

• Slippery and shifty fabrics. Viscose, rayon challis, silk, satin and chiffon are the fabrics where a rotary cutter earns its place. Weight the pattern down, roll along it, and the piece comes out true to the pattern. Sewing viscose without tears starts with cutting it this way.
• Long straight lines. Skirt panels, trouser legs, waistbands, ties and bias strips. With a clear acrylic ruler you can cut a strip to an exact width without drawing a line first.
• Several layers at once. Cutting the two halves of a T-shirt front, or four pocket bags, in one pass.
• Knits. Jersey curls and stretches when scissors lift it; under a rotary cutter it stays flat.
• Pattern paper and fabric together. A rotary cutter cuts through the printed pattern and the fabric in one go, which saves tracing. Keep a separate blade for paper if you do this often, since paper dulls blades faster than cloth.

When are scissors better?

• Tight curves. Necklines, armholes, the crotch curve of trousers and the scoop of a bucket hat crown. A 45 mm blade cannot follow a curve that tight without wandering; a 28 mm blade can, with care, but scissors do it with no effort.
• Notches and snips. The small cuts at seam lines, the clipping into a curved seam allowance, trimming a corner.
• Thick and bulky fabric. Denim, wool coating, boiled wool, fleece and quilted fabric. A large blade cuts them, but it takes real pressure and the blade dulls quickly. Long, heavy shears with a bent handle cut them calmly.
• No table. Cutting on the floor, on a bed, or on a small kitchen table where a mat will not fit. Scissors need nothing under the fabric.
• Small or fiddly pieces. Cuffs, collar stands, pocket flaps and bag corners are quicker to snip than to steer a blade around.

Which rotary cutter size should you buy?

Rotary blades come in three common sizes. Buy the 45 mm (1 3/4 in) first; it does most of the work.

• 45 mm (1 3/4 in): the all-rounder for garment pieces, strips and up to four layers of medium-weight fabric.
• 28 mm (1 1/8 in): for curves and small pieces. Many people cut the body of a garment with the 45 mm and swap to the 28 mm for necklines and armholes.
• 60 mm (2 3/8 in): for thick fabrics and stacks of layers. Heavy, and hard to steer around anything but a straight line.

Choose a handle with a blade guard you can operate with one hand, and get into the habit of retracting the blade every time you set the cutter down. A rotary blade is as sharp as a razor, and most cuts happen when a hand reaches across a table for a ruler.

A self-healing mat is not optional. Cutting on a table top blunts the blade in one session and scores the table. A mat of 60 × 90 cm (24 × 36 in) covers most garment pieces; an A2 mat of 45 × 60 cm (18 × 24 in) works if you move the fabric between cuts.

What scissors do you need for sewing?

Three pairs cover a sewing room, and they must never be lent to anyone who cuts paper.

• Dressmaking shears, 20 to 25 cm (8 to 10 in), with a bent handle so the lower blade stays flat on the table while your hand sits above it. This is the pair that cuts out garments.
• Small snips or embroidery scissors, 10 to 13 cm (4 to 5 in), for notches, threads and clipping curves.
• A paper pair, any cheap scissors, for patterns and interfacing backing paper, so the shears stay sharp.

Pinking shears are a seam finish, not a cutting tool; they cut slowly and the zigzag edge makes matching pattern pieces harder.

How do you cut accurately with each tool?

With scissors, take long strokes and cut with the middle of the blades, never closing the tips, which leaves a small jag at each stroke. Keep the lower blade on the table and move around the fabric rather than turning the fabric toward you. Pin inside the seam allowance so the pin heads do not catch the blade.

With a rotary cutter, hold the pattern down with weights rather than pins, since pins stop the fabric from lying flat. Stand up, cut away from your body, and keep the blade upright against the edge of the pattern or the ruler. On curves, make several short rolls, lifting the blade and repositioning, rather than trying to steer through the whole curve in one motion. For either tool, the layout and grain matter as much as the blade: laying out and cutting fabric on grain is where accuracy begins.

Whichever you use, notches still have to be marked. Cut them outward as small triangles with the tips of your snips, or mark them with chalk inside the seam allowance; Sewly's printed patterns include the seam allowance, so you cut on the outer line and mark the notches as you go.

Which should you choose?

• Your first cutting tool: good dressmaking shears. They cut every fabric, need no table or mat, and you will use them for notches and trimming for the rest of your sewing life.
• You sew mostly cotton and linen garments: shears are enough. Add a rotary cutter when you find yourself cutting long strips or bias binding.
• You sew viscose, silk, satin or knits: a 45 mm rotary cutter and a mat will improve your results more than any other purchase.
• You cut many layers or sew for several people: rotary cutter, a large mat and a long ruler.
• You sew denim, coating or fleece: long heavy shears; a 60 mm rotary cutter if you also want speed on straight seams.
• You cut on the floor or a small table: scissors, and a kitchen table big enough for a mat later.

Keep both sharp. A rotary blade is replaced when it starts skipping threads; shears go to a sharpener once a year or so, and only cut fabric in between.