Sewing glossary

Plain-English definitions of the sewing terms used in the Katagami guides. Some of these — on the fold, grain and notch — also appear as labels on the printed pattern pieces.

Right sides together

Placing two pieces of fabric with their right (outer) faces together before sewing. After stitching, you turn the piece right side out through a gap so the seam is hidden inside. This is the basic method for bags and clothing.

💡 The "wrong" side of fabric is usually the paler / less shiny face. For solids, the shinier face is often the right side.

Seam allowance

The margin added outside the finished (seam) line for sewing. A common default is 1–1.5 cm on straight seams, with 2–4 cm on hems for folding. In Katagami you can set it from 0–3 cm and the pattern is output with the seam allowance included.

See also: the sewing guides for where each value is used.

Seam line & cutting line

A pattern has two outlines: the seam line (the finished shape) and, outside it, the cutting line (where you cut the fabric). The space between them is the seam allowance. Katagami can show or hide the seam line.

Turning gap

A short unsewn opening left in a seam so you can turn the piece right side out. After turning and pressing, close it with a few hand stitches or by topstitching.

Double-fold hem

Folding a raw edge under twice so no raw edge shows, then stitching. The standard, tidy way to finish hems and openings. Pressing the folds first makes it much easier.

Hem

The finished bottom edge of a garment or item. Usually made by folding the edge under (often a double-fold) and stitching. On stretch fabric, use a twin needle or zigzag so the hem stretches.

Zigzag stitch & serger

A zigzag stitch on a home machine, or a serger / overlocker, finishes raw edges so they don't fray. A narrow zigzag also adds stretch, which is useful for knits when you don't have a serger.

Bias tape

A narrow strip cut on the bias (45°), so it stretches and curves smoothly. Used to bind or finish edges such as necklines and armholes. See how to attach bias tape.

Ribbing

A stretchy knit fabric used for cuffs, neckbands and hems. It hugs the body and springs back to shape, giving a clean, professional finish on knit garments.

Notch

A small matching mark on the edge of a pattern or fabric. Lining up the notches keeps pieces aligned when you sew — especially helpful on curves like armholes. Katagami draws notches as short marks on the pieces.

On the fold ("wa")

Placing the marked edge on a fold of the fabric so the piece is cut as one symmetrical (mirror-image) shape with no center seam. On the pattern, this edge is labeled "fold". (The Japanese term is wa, 輪.)

Grain / grainline

The direction of the fabric's threads. The grainline arrow on a pattern should run along the lengthwise grain so the piece hangs and stretches correctly. Katagami marks the grainline on each piece.

Gathers & easing

Gathering draws fabric up into small folds to add fullness (as in a gathered skirt). Easing is gently fitting a slightly longer edge to a shorter one (as at a sleeve cap) without visible folds.

Gusset

An added depth at the base or side of a bag or garment that gives it three-dimensional volume. Boxing the corners of a tote, for example, creates a base gusset.

Ease

Extra room added beyond the body measurement so a garment is comfortable to move in. More ease = a looser, more relaxed fit. In Katagami, ease is one of the values you can adjust.

Basting

Long temporary stitches (by hand or machine) used to check the fit or hold pieces together before final sewing. Easy to remove. Basting first is recommended for necklines and armholes.

Interfacing

A stiffening material fused or sewn to fabric — collars, facings, bag bodies and zipper areas — to add body and help the piece keep its shape. Comes in light, medium and heavy weights.

💡 Test-fuse a scrap first to check the bond and the resulting stiffness.

Facing

A piece sewn to an edge such as a neckline and turned to the inside to finish it neatly, so no seam allowance or binding shows on the outside. Often backed with interfacing for stability.

💡 “Stitch in the ditch” or understitch keeps a facing from rolling to the outside.

Slip stitch

Nearly invisible hand stitches used to close a turning gap or finish a hem from the inside. You catch just a thread or two of the outer fabric so the stitches barely show on the right side.

💡 A machine blind-hem stitch or a topstitch is a faster alternative when invisibility isn't essential.

Topstitch

A line of stitching visible on the right side. It holds seam allowances flat and adds a crisp, professional accent. Sew an even distance from the edge for the best look; heavier or contrasting thread makes it stand out.

💡 Use the presser-foot edge or a strip of tape as a guide to keep the distance even.

Stay tape

A narrow fusible tape ironed onto edges that shouldn't stretch — knit shoulders, necklines, zipper openings — to stabilise them. It keeps the measurements from growing as you sew.

💡 Half-bias stay tape eases around curves more readily than the straight type.

Self fabric

The same fabric as the main piece. Making bias tape, facings, handles or loops from self fabric gives a coordinated look. Allow for these parts when buying and cutting your fabric.

💡 Keep leftover fabric — it's handy for future bias tape or small projects.

Casing (elastic channel)

A tunnel of fabric that holds elastic or a drawstring, most often at a waist or cuff. You make it by folding the edge under (usually a double-fold) and stitching, then threading elastic through. Pants, skirts, bloomers and snoods all use a casing.

Thread the elastic with a bodkin or safety pin, easing it through a little at a time. Overlap and stitch the ends, then close the opening.

💡 Pin the free end of the elastic to the fabric before you start so it can't disappear inside, and leave a 2–3 cm opening to thread through.

Clipping curves & corners

Small cuts into the seam allowance that let curves and corners sit smoothly once turned. On inner (concave) curves such as necklines, clip straight cuts up to just short of the seam line so the allowance can spread.

On outer (convex) curves, cut small notches (wedges) to remove bulk; at corners, trim the allowance diagonally close to the stitching for a sharp point. In every case, don't cut the stitches.

💡 Stop each clip 1–2 mm short of the seam line. Cut too far and the seam will gape open.

Pressing seams open / to one side

Setting a seam with the iron after stitching. Pressing open means spreading the allowance to both sides and pressing it flat; pressing to one side means laying both layers the same way.

Open seams lie flat and spread the bulk; seams pressed to one side are stronger and common on knits and curves. A good press before the next step makes a big difference to the finish.

💡 Press by lifting and pressing down rather than sliding — it sets a crisp crease and avoids stretching the fabric.

Turn right side out

Reaching through the turning gap to pull the right side of a sewn bag or piece to the outside. This hides the seam allowance inside and reveals the finished face.

Ease corners out gently with a point turner or chopstick, and shape curves with your fingers. Press the edges afterwards, and topstitch if you want the shape to hold.

💡 Only push corners from the inside — jabbing hard can pierce the fabric. A blunt point turner is safest.

Press cloth

A cloth laid over the fabric to protect it from the iron's heat and pressure. Thin cotton, gauze or a tea towel works well.

Faux leather, knits, dark colors and any surface where you fuse interfacing can scorch, shine or ooze adhesive under a hot iron, so a press cloth is essential. It's also a safeguard when pressing from the right side.

💡 To fuse interfacing, press through a cloth by holding firm pressure for a few seconds, moving section by section, for even bonding.

Pre-washing & straightening grain

Prep done before cutting: pre-washing shrinks the fabric, and straightening the grain squares up the weave. Cotton and linen shrink in the wash, so shrinking them first prevents a garment from distorting later.

Soak the fabric for about an hour, dry in the shade, then press while just damp — easing warp and weft back to right angles as you go.

💡 Knits and fabrics with no "washable" label tend to shrink. You can skip this for small items, but pre-wash for clothing to be safe.

Sewing into a tube

Rolling a rectangle of fabric right sides together and sewing the long edge to form a tube. It's the basis for loop-shaped parts — headbands, snoods, sleeves and handles.

After sewing, turn it right side out so the seam allowance is hidden inside. For a narrow tube, a loop turner or safety pin makes turning much easier.

💡 Very thin tubes are hard to turn. Keep the seam allowance narrow, or use a loop turner for cord-like straps.

Stitch length

How long each machine stitch is. A standard setting on a home machine is 2.0–2.5 mm; a larger number gives longer stitches, a smaller number gives finer ones.

Use the longest length (around 4 mm) for gathering so the threads pull easily, and shorter stitches to reinforce curves and seam ends. Longer for thick fabric, shorter for thin fabric.

💡 Backstitch (2–3 stitches in reverse) at the start and end of a seam so it won't unravel when pulled.

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