Sewing pattern glossary

Seam line (stitch line)

The solid line on every generated piece where two edges are meant to be sewn together. Drafting formulas place points and curves on this line first; everything else, including the cutting line, is built outward from it.

Cutting line

The dashed outer line on generated pieces, offset from the seam line by the selected seam or hem allowance. Cut the fabric on this dashed line and sew on the solid line inside it.

Seam allowance

The extra fabric between the seam line and the cutting line, commonly 0.7 to 1.5 cm. The generators let you set allowance values, and the dashed outline in the preview already includes them.

Hem allowance

A deeper allowance at a lower edge, such as a skirt, pants, or sleeve hem, used for folding and finishing. It is often 2 to 4 cm, noticeably larger than a regular seam allowance, so check it before cutting.

Grainline

The long arrow printed on each generated piece. Align it parallel to the fabric's lengthwise threads, which run parallel to the selvage, so the garment hangs straight and does not twist after sewing and washing.

Bias

The 45-degree direction across the fabric grain. Fabric stretches most on the bias, which is useful for bindings and drapey styles, but it also makes curved edges such as necklines and armholes easy to distort while handling.

Selvage

The tightly woven, non-fraying edge running along both sides of a length of fabric. It marks the lengthwise grain: place the grainline arrows on printed pattern pieces parallel to the selvage during layout.

On fold

A layout instruction to place a marked pattern edge exactly on a fold of the fabric, so a symmetrical piece such as a back, neckband, or waistband is cut as one whole shape instead of two halves.

Notch

A small tick mark on the seam line used to match pieces accurately: front to back at side seams, sleeve cap to armhole, waistband to waistline. Transfer notches to the fabric before removing the paper pattern.

Fold line

A line showing where the fabric itself is folded during construction, for example on hems, cuffs, waistband facings, or patch pocket tops. It is different from cutting on the fold, which happens at layout.

Dart

A stitched wedge that removes excess fabric and shapes flat cloth around the bust, waist, or hips. Generated skirt, bodice, dress, and pants blocks place darts based on the difference between adjacent measurements, such as waist and hip.

Ease

The difference between body measurements and finished garment measurements. Wearing ease is the minimum room needed to move and breathe; design ease is extra fullness added for style. The fit presets in each generator mainly control ease.

Walking ease

Extra width or an opening, such as a vent or flare, near the hem of straight skirts and dresses so you can take a normal step. Narrow-hem silhouettes without walking ease noticeably restrict movement.

Block (sloper)

A basic, minimally styled pattern drafted from body measurements and used as a foundation for developing designs. Nastix Patterns generators produce blocks, such as skirt, bodice, sleeve, dress, and pants, that you can fit once and reuse.

Muslin (toile, test garment)

A trial version sewn from inexpensive fabric to check fit before cutting the final material. For generated drafts it is the most important step: it reveals ease, dart, and length issues while corrections are still cheap.

Test square

A calibration square of known size printed on exported PDF files. Measure it with a ruler after printing at 100% scale; if the square is off, every pattern piece on the page is off by the same ratio.

Tiled PDF and copyshop PDF

Two print formats of the same draft. A tiled PDF splits the pattern across A4 pages for home printing and taping; a copyshop PDF keeps the pieces on one large sheet for wide-format plotter printing.

Armhole (armscye)

The opening in a bodice, dress, T-shirt, or tank top where the sleeve or armhole finish attaches. Its measured curve length must stay compatible with the sleeve cap, facing, or binding that will be sewn into it.

Sleeve cap and cap ease

The curved top of a sleeve that sews into the armhole. In fitted woven blocks the cap is slightly longer than the armhole, which is called cap ease, so the sleeve can round over the shoulder; knit sleeves use little or none.

Neckline

The opening around the neck, drafted as round, deep round, or V-shaped in the generators. Its measured curve length drives dependent pieces such as neckbands, collars, and neck facings, so keep values consistent between tools.

Neckband

A stretched strip of knit fabric sewn around a T-shirt or tank top neckline. The generator drafts it shorter than the neckline itself, typically around 80 to 90 percent, so it pulls the opening flat against the body.

Facing

A shaped piece that mirrors an edge, such as a neckline or armhole, and turns to the inside to finish it cleanly. The neck facing and armhole facing generators draft these pieces to match your bodice or dress curves.

Interfacing

A stabilizing layer, usually fusible, applied to the wrong side of pieces that need body: waistbands, collars, cuffs, facings, and pocket flaps. It keeps edges crisp and prevents stretching during sewing and wear.

Waistband

The band that finishes a skirt, pants, or shorts waist. The waistband generator drafts straight, contour, and elastic versions from the finished waist measurement plus overlap, so its length must match the garment's sewn waistline.

Vent

A finished opening at the bottom of a seam, usually at the center back of a straight or pencil skirt, that adds walking room. The skirt vent generator drafts the underlap and facing extensions for you.

Crotch curve

The J-shaped seam on pants and shorts pieces that connects the waist to the inseam. The back curve is longer and deeper than the front to cover the seat, and both must join the inseam in a smooth line.

Rise (crotch depth)

The vertical distance from the waist to the crotch line, measured seated or taken from well-fitting pants. It controls where the crotch curve sits: too short cuts in, too long bags under the seat.

Inseam and outseam

The inner leg seam from crotch to hem and the side seam from waist to hem. On generated pants and shorts, compare front and back inseam lengths before cutting; they must sew together without forcing or stretching.

Princess seam

A vertical shaping seam running from the shoulder or armhole over the bust down to the waist or hem, replacing darts. It splits a bodice into center and side panels and gives a smooth, easily adjustable curved fit.

Yoke

A fitted horizontal panel across the shoulders of a shirt or across the back of the hips on skirts and pants. It replaces darts in that zone and creates a seam that is useful for both design and fit adjustments.

Stay-stitching

A line of regular machine stitching placed just inside the seam line on curved raw edges, such as necklines and armholes, right after cutting. It stops bias-leaning curves from stretching out of shape while you handle the pieces.

Understitching

A row of stitching that secures the seam allowances to a facing, sewn close to the seam. It makes neck and armhole facings roll to the inside and stay invisible instead of popping out during wear.

Topstitching

Visible stitching sewn from the right side, parallel to a seam or an edge. It flattens allowances, adds durability, and defines details; the patch pocket and pocket flap generators include topstitch guide lines in the draft.

Stretch percentage

How much a knit fabric extends across the grain: 10 cm that stretches comfortably to 13 cm has 30 percent stretch. T-shirt and tank top drafts assume moderate stretch, so measure your fabric before relying on negative ease.

Recovery

A knit fabric's ability to return to its original size after being stretched. Fabric with poor recovery grows during wear, so neckbands, bindings, cuffs, and fitted knit garments need fabric that snaps back, usually containing elastane.

Drag lines

Diagonal wrinkles that appear on a sewn garment when it is pulled off balance, pointing toward the area that is too tight or too short. Reading drag lines on a test garment tells you which measurement or ease value to adjust.