Measure, cut, mark and press fabric accurately

The basic tools and what each is for, cut size from finished size, cutting on grain, marking that comes out, and pressing at a setting you tested on a scrap.

1. The basic kit Understand

Oregon State's 4-H equipment sheet lists the basic tools and marks the rest as optional (OSU Extension, Sewing Equipment). It asks two questions before you buy anything else: how often you will use it, and whether you could borrow it. Convention

Two notes from the same sheet. Pinking and scalloping shears, with their zigzag blades, finish the seams of firmly woven or non-raveling fabrics; OSU calls them too inaccurate for cutting out, and its cutting sheet says they do not leave the smooth edge you guide a seam along. Keep them for seam finishes (Seams and a first piece). And OSU advises against attaching a magnetic pin holder to a computerized machine; Your machine covers keeping magnets and pins away from small children.

Pressing tools beyond the iron are optional on a first project. Utah State's supplies list defines them and files the ham and press cloth under advanced project supplies (USU Extension, Basic Sewing Supplies): a press cloth goes between the iron and the fabric to prevent shine and press marks; a tailor's ham is a firm, rounded cushion for pressing curved seams and darts over a curve like the body's; a seam roll is a long cushion for seams in narrow places such as sleeves; a clapper (pounding block) is a wooden block that holds heat and pressure on a seam while it cools. A clean scrap of plain cotton works as a first press cloth. Preference

Rotary cutter, mat and ruler

A rotary cutter is a round, replaceable blade on a handle, rolled along the edge of a ruler on a self-healing cutting mat. OSU's sheet describes it with a retractable guard and says to use it on a mat; OSU and Kentucky's 4-H junior guide both say young sewers use one with adult supervision (UK Extension, 4-H Sewing Junior Level). OLFA's product page for one of its cutters describes a split blade cover that exposes one edge at a time while the other half stays guarded (OLFA, 45 mm RTY-2/NS rotary cutter). Product-specific A rotary cutter is fast and accurate for straight pieces such as pillowcase panels and straps. It is not in the basic kit; shears do every cut in this manual.

2. Cut size, seam allowances and units

A seam allowance is the fabric between the cut edge and the stitching line, the seamline. Every piece is cut larger than it will be finished by its seam allowances. For a rectangle with a seam on each side:

cut width = finished width + 2 × seam allowance, and the same for length.

Utah State's Four Square Pillow shows the arithmetic (USU Extension, Four Square Pillow). Two 8 in squares joined with a 1/2 in seam measure 8 + 8 − 1 = 15 in across. With 1/2 in taken by the seam on each outer edge, the finished cover is 15 − 1 = 14 in, the size of its 14 in pillow form. Read the other way: a 14 in finished size plus 2 × 1/2 in is a 15 in cut. Physical principle Utah State's tied pillow adds the reason the finished cover equals the form rather than exceeding it: it should fit snugly. The pillow calculator in Your project follows that convention.

The cut-size calculator does this for any rectangle, with a separate top and bottom allowance for a hem or casing, and a fabric estimate across the width you measured after washing. Record each piece in the cut list.

The pillowcase pieces

Utah State's Designer Pillowcase gives its pieces directly (USU Extension, Designer Pillowcase), for fabric at least 42 in wide:

USU's finished standard case is 20 1/2 × 30 in, and the width checks against the rule: the 42 in piece folds to 21 in, and a 1/2 in side seam leaves 20 1/2 in. The pillowcase cut list rows are already seeded with the standard sizes. Kentucky's 4-H guide cuts its pillowcase body 27 in by the full 44/45 in width and sews it with 5/8 in seams, so the same project comes in more than one set of numbers; use one project's pieces and its seam allowance together.

Seam allowances and units

Seam allowances are a convention, and they vary. Oregon State's seams sheet calls 5/8 in (1.5 cm) standard in US commercial patterns; extension flat projects often use 1/2 in; quilting uses 1/4 in; some European patterns include none and expect you to add them. Convention Seams and a first piece covers them in full. For cutting, the rule is that the cut size and the seam allowance come from the same set of instructions.

NIST defines the inch as exactly 25.4 mm, so 1 in = 2.54 cm and 1 yd = 0.9144 m, exactly (NIST, SI Units: Length). Physical principle Patterns round their metric equivalents: 5/8 in is 1.5875 cm, printed as 1.5 cm.

Measure in one system for one project. Switching halfway is where a piece comes out a few millimeters short.

3. Cutting on grain

Cutting is where the grain work in Choosing and preparing fabric pays off or is lost. Oregon State's cutting sheet gives the method (OSU Extension, Cutting Skills):

• Lay the fabric flat and square. On a table, folded selvage to selvage if the pieces are cut on the fold, with the squared end lined up.
• Check the grainline at both ends. For a pattern piece, measure from each end of its grainline arrow to the selvage; the two distances must match. Utah State's tied pillow pins one end of the arrow and pivots the piece until they do. For a rectangle with no pattern, measure from the squared end and from the selvage, and mark the corners with a ruler.
• Pin perpendicular to the cut edge, inside it, not over it.
• Cut with bent-handled shears, holding them upright, in long, firm, smooth strokes that use all but the tips of the blades. Slide the lower blade along the table rather than lifting the fabric.
• Cut notches outward, as small points beyond the cutting line, so the seam is not weakened and the notches show for matching. A notch is a matching mark on a cut edge.
• Save the scraps. OSU: they are for testing tension, stitch length, iron temperature and pressing.

Curved garment pieces get one more step. Staystitching is a row of regular-length machine stitching just inside the seamline, through one layer, done right after the piece is cut and marked, so the curve does not stretch before it is sewn. A pillowcase has no curves and needs none.

Utah State's skirt project recommends cutting off the selvages, which shrink more than the rest of the fabric and can pucker a seam (Choosing and preparing fabric). For a pillowcase cut selvage to selvage, trim them before you measure the 42 in.

Your posture. OSHA's guide to scissor work in sewing shops names the strain points: bending over the table, long reaches across the fabric, and awkward wrists (OSHA eTools, Scissor Work). Its fixes apply at home: a table near elbow height, bringing the fabric to you instead of reaching, and sharp tools that take less force. Convention A kitchen counter is often closer to elbow height for cutting than a dining table.

4. Marking

Marking transfers what the pattern or your plan says to the fabric: seamlines, fold lines, dots for matching, the placement of a pocket or buttonhole. The mark has to show while you sew and then disappear. Oregon State's equipment sheet describes the common tools and their traps:

The rule under every row is to test the marker on a scrap of the real fabric, then wash the scrap the way the item will be washed. Test it We add one precaution of our own: also press over a test mark before you trust it, since some marks react to heat as well as to hot water, and you will press long before the first wash.

Tailor's tacks work on any fabric, including ones no marker shows on. Oregon State's hand-sewing sheet describes them (OSU Extension, Hand-Sewing Skills): with a long double thread and no knot, take a small stitch on the pattern line through the pattern and fabric, leaving a 1 in (2.5 cm) end; repeat every 2 to 3 in with slack thread between; then cut the threads and ease the pattern off without pulling out the markings. For a dot, loop the thread instead, and cut the loops before you remove the pattern.

5. Pressing, and the iron

Sewers press rather than iron. UF/IFAS Extension's 4-H sheet gives the difference (UF/IFAS, Ironing versus Pressing): ironing slides the iron back and forth to smooth wrinkles; pressing lifts the iron and sets it down on one spot. New Mexico State's guide calls it "lower and lift," and explains that it puts pressure where you need it without stretching the fabric. Convention Sliding a hot iron along a cut edge or across the bias pulls it out of shape; Utah State's Four Square Pillow makes the same point about keeping the grain straight.

Iron safety

The same manual says its auto shutoff turns the iron off after about 1 minute motionless on its soleplate or side and 30 minutes on its heel. Shutoff times vary by model, and a shutoff is a backstop, not a reason to walk away. Product-specific It also says to plug the iron into a circuit without another high-wattage appliance running, and that steaming on a low setting, or before the iron has heated for about 2 minutes, can drip hot water.

For a small burn, the American Burn Association's first-aid page says to cool it with running water, cool but not cold or icy, for at least 5 minutes; its pages on contact and scald burns, which name irons and steam, say 10 to 20 minutes (ABA, Burn First Aid; ABA, Contact Burns; ABA, Scald Burns). Remove rings and nearby clothing, and cover the burn loosely. Do not use ice, butter or oils, and do not break blisters.

Setting the iron

Set the iron from the label and a test on a scrap, not from a number:

1. Start from the care words and the fiber. Set the iron for the fiber content (UF). For a blend, use the setting for the most heat-sensitive fiber: a poly-cotton blend is pressed at the polyester setting, not the cotton one (UF, Oregon State's pressing sheet, NMSU).
2. Test on a scrap. Press a scrap of the same fabric, with and without steam, and look for shine, scorching, melting, puckering or water spots (NMSU, OSU). Raise or lower the setting and test again. Test it
3. Use a press cloth where it helps. UF: a press cloth prevents shine, scorching and melting. When a fabric's setting is below the iron's steam range, a dampened press cloth gives the moisture without dripping (UF; OSU Extension, Pressing Skills). NMSU: almost all pressing is from the wrong side; use a press cloth when you press on the right side.
4. Write the setting down. The fiber, the dial position, steam or not, and press cloth or not, in the notes column of the stitch sample log beside that fabric, so Seams and a first piece starts from it.

Then the habits that apply to every piece. Press each seam before another seam crosses it (NMSU, UF, OSU). Do not press over pins: UF notes they can mark the fabric and melt plastic pin heads. Use light pressure, keeping most of the iron's weight in your hand (OSU). For cutting out, a warm, dry iron flattens pattern tissue (UF).

A cotton pillowcase is the easy case: cotton takes a high setting and steam (the table in Choosing and preparing fabric), so most cotton pieces press flat without a cloth. The test on a scrap still comes first, because a finish or a print can behave differently from the fiber.

Pressing a fold to a measured width

Hems, casings and the pillowcase's own seams start as a pressed fold. Set the seam gauge's slider to the width, 1/2 in for the practice. Fold the edge to the wrong side, check it against the gauge, press a few inches, move on and check again. Pressing each section before you measure the next keeps the fold from creeping wider. Preference

6. See it: Dana cuts her pillowcase See it

• USU Extension, Designer Pillowcase: the cut table used above, with the instructions Seams and a first piece sews from.
• OSU Extension, Cutting Skills: photographs of holding bent-handled shears and cutting notches outward.
• UF/IFAS, Ironing versus Pressing: a two-page sheet on the lift-and-lower motion and the blend rule.

7. Practice: cut and press the pillowcase pieces Practice

Minimum: the two pillowcase pieces cut on grain, an iron setting tested on a scrap, both pieces pressed, and one 1/2 in fold pressed to the seam gauge. Time: about an hour. Materials: the preshrunk, squared fabric from Choosing and preparing fabric; shears and scissors; a tape measure and a yardstick or long ruler; a seam gauge; chalk or a marker you have tested; pins; an iron and ironing board; a scrap of the same fabric.

1. Check the kit. Go through the table in section 1 and add anything missing to the shopping list.
2. Confirm the sizes. Open the cut list: border 9 × 42 in, body 27 × 42 in (or the queen or king body). If your washed fabric is narrower than 42 in after trimming the selvages, see Common mistakes below before you cut.
3. Test the marker. Mark a scrap, press over the mark, and remove it the way the marker says.
4. Mark and cut the border. Measure 9 in from the squared end at both selvages and the middle, join the marks with the ruler, and cut with long, smooth strokes.
5. Square, mark and cut the body. Check that the new edge is square to the selvage, then mark and cut 27 in the same way. Mark both pieces cut in the cut list and set the grain to crosswise.
6. Set and test the iron. Choose the setting from the fiber, press a scrap with and without steam, adjust, and write the setting in the notes of the stitch sample log.
7. Press the pieces and one fold. Press both pieces from the wrong side, lifting and lowering. On a scrap, press a 1/2 in fold, checking it with the seam gauge every few inches.

8. Your sewing Your sewing

9. Check your work Check your work

Criteria

• Is each piece the size in the cut list, measured at both ends and the middle?
• Does each piece fold in half with its edges and corners meeting?
• Do the edges look smooth, without the steps that short, choppy cuts leave?
• Did you test the iron setting on a scrap, and is the setting written down?
• Are the pieces pressed flat without shine, scorch marks or stretched edges?
• Does the pressed fold measure 1/2 in along its whole length?
• Did the marks come out of the test scrap after pressing?

Worked example

Dana's fictional pieces measure 9 × 42 and 27 × 42 in at both ends and the middle, and each folds square. One stretch of the border edge is stepped where she stopped the shears near the tips; it lies inside the 1/2 in seam allowance, so she trims it straight rather than recutting. Her scrap test and setting are logged. Her pressed fold measures 1/2 in for most of its length and 5/8 in at one end, where she pressed two sections before checking; she re-presses that end. Against the criteria, both pieces are ready for Seams and a first piece.

Common mistakes

• Fabric narrower than the pattern's width. If your washed fabric is under 42 in after trimming the selvages, the case will be slightly narrower; for a pillowcase that is usually acceptable, but check the finished width against your pillow before you cut. For a fitted piece, the layout or the fabric changes instead.
• Measuring from the store's cut end. Measure from the squared end (Choosing and preparing fabric).
• Short, choppy strokes. They leave a stepped edge. Use the length of the blades.
• Lifting the fabric to cut. It shifts the layers. Keep the lower blade on the table.
• Sliding the iron along a cut edge. It stretches it. Lift and lower.
• Pressing over pins or untested marks. Pins mark and melt; some marks set.
• Leaving the rotary cutter open on the table. Close the guard every time.

What is still unresolved

Whether your setting suits the pressing a seam needs is settled when you press the first seams in Seams and a first piece, where the fabric is doubled and steam builds up in the allowances. Whether a pattern's printed seam allowance is the one its cut sizes assume is settled by its own instructions, read before you cut (Patterns and fit).

10. Knowledge check and scenario

Checklist

• The pillowcase pieces are cut on grain and pressed, and the cut list has their sizes marked cut.
• My kit is checked and anything missing is on the shopping list.
• The iron setting for this fabric is tested on a scrap and written down.
• I pressed a 1/2 in fold that measures true along its length.
• I compared two marking tools on a washed scrap, or cut practice strips with a rotary cutter and closed guard. (Go deeper; optional)