There are two tools for cutting cloth and they are not competitors. Shears and a rotary cutter do different jobs, and most people who sew keep both.
Shears: the versatile default
Fabric shears cut a curved line, a single layer, and a corner. They work on any fabric, they do not need a mat, and a good pair can be sharpened for decades. They are the tool you reach for when the line is not straight.
The rotary cutter: straight lines and layers
A rotary cutter cuts a straight line along a ruler, through several layers at once, faster than shears. It cannot turn a corner, it needs a self-healing mat underneath, and its blade is always exposed whenever the guard is open. For strip cutting and quilt pieces it is far more accurate than shears.
| Task | Shears | Rotary cutter |
|---|---|---|
| Long straight cut | Works | Faster and straighter |
| Curved seam | Yes | No |
| Multiple layers | Difficult | Up to six |
| Cutting on a table with no mat | Yes | No |
| Corners and notches | Yes | Needs a snip afterwards |
Both tools will cut you
Keep the hand holding the fabric behind the blade line, never in front of it. Close a rotary cutter guard after every cut, even if you are coming straight back. Cut away from your body, and store shears closed.
Grain, and why it decides everything
Woven fabric has a warp running along the length and a weft running across. The warp is the stable direction. A pattern piece has a grain line drawn on it, and that line must run parallel to the selvedge, not to the table edge and not to the cut edge of the cloth.
Cut a piece off-grain and the cloth will pull it out of shape as it hangs. A skirt cut off-grain twists at the hem; a sleeve cut off-grain spirals. It is the least visible mistake in cutting and the most visible one on the body.
Square the fabric first
Fold it, or pull a thread across and cut along the line it leaves, so you have a true edge to work from.
Lay the pattern on the grain
Measure from the grain line to the selvedge at both ends of the line. If the two distances differ, the piece is on the bias.
Weight or pin, not both
Pattern weights hold the whole edge; pins hold one point. On fine or coated fabric, weights leave no marks.
Mark before you move anything
Notches, darts and the balance points while the pattern is still on the cloth. Once the pattern is off, those marks are gone.
Cut, then check
Lift the pattern and check every notch and every piece is there before you clear the table.
Marking tools
Tailor's chalk is compressed clay or wax that sits on the surface and brushes off. A tracing wheel transfers a line by pressure, through dressmaker's carbon or straight into the cloth. Both beat a pen: ink markers can leave a permanent residue on fine fibre, and they are the tool most likely to ruin a good piece of cloth.
Mark on the wrong side
Every mark you make should be on the inside of the garment. Chalk and carbon are meant to be invisible in the finished piece, so if you can see it from the outside, you are marking the wrong face.
The habit that separates clean cutting from messy cutting is simple: mark the cloth while the pattern is still pinned to it, and check the grain of every piece before you cut the next one.
