CUT & SEW

What a tech flat is

A tech flat is a clean, flat line drawing of a garment, front and back, like it is laid on a table. No body, no pose, no shading. It shows every seam, stitch line, pocket, label and trim, drawn to scale.

• Why it matters. A factory or sample maker cannot read your mind or a mood board. The flat shows exactly what to build, so the sample comes back right the first time. Every round of samples costs time and money.
• Where it goes. Flats are the first pages of a tech pack. The pack adds the measurements for every size, the materials list (fabric, thread, zippers, labels), how it is sewn and where the artwork goes.
• How it is used. Idea, then flats, then the tech pack, then a first sample (proto), then a fit sample, then fixes, then production. Brands also use flats for line sheets to show stores what is coming.
• Flat vs. fashion drawing. A fashion drawing sells the mood. A flat is a blueprint. Keep both, but the factory needs the flat.
• Here. Go to step 4, Tech pack, fill in what you know, tap FLAT on the viewer. Save makes the flats (to edit in Illustrator or Inkscape) and the full tech pack PDF.

Get your measurements right

Measuring a body

• Use a soft tape measure. Wear thin, close fitting clothes or measure over underwear.
• Snug, not tight. You should be able to slide one finger under the tape.
• Keep the tape level all the way around. Use a mirror, or better, have a friend do it.
• Stand relaxed, feet together, breathe normally. Do not suck in.
• Measure twice. If the two numbers are different, measure a third time.
• Each box in step 3 tells you exactly where that measurement goes.

Measuring a garment

• Lay it flat on a hard surface. Smooth it with your hands, never stretch it. Button and zip it.
• Measure straight across from edge to edge. That is a "flat" or half measure. Double it to get all the way around.
• Length on tops starts at the high point shoulder: where the shoulder seam meets the collar.
• Pants: waist across the top of the waistband, inseam from the crotch seam down the inside leg to the hem.
• No tape measure? Use "Measure a piece you own" and a sheet of printer paper.

Sewing machine basics

You only need one stitch to start: a straight stitch. Everything else is practice.

1. Thread it. Follow the numbers printed on your machine from the spool to the needle. Put a full bobbin in the bobbin case. Pull both threads to the back.
2. Set the stitch. Straight stitch, length about 2.5 mm. Use a universal needle for woven fabric, a ballpoint or jersey needle for knits, a denim needle for thick fabric.
3. Needle down, foot down. Turn the hand wheel toward you to drop the needle into the fabric. Lower the presser foot. The machine will not feed the fabric with the foot up.
4. Lock the start. Sew 3 or 4 stitches forward, hold the reverse lever and sew 3 or 4 back, let go and keep going. This backstitch keeps the seam from pulling apart.
5. Drive it. The foot pedal is the gas. Press gently and keep a steady speed. Your hands only guide the fabric, let the machine pull it. Never push or drag it.
6. Keep the edge on the line. Line the fabric edge up with the seam guide on the plate (our patterns use 3/8 in and 1/2 in seams).
7. Turn a corner. Stop with the needle down in the fabric, lift the foot, turn the fabric, foot down, keep going.
8. Lock the end. Backstitch 3 or 4 stitches again at the end. Lift the foot, pull the fabric out, cut the threads.
9. Press as you go. Iron every seam after you sew it, before you sew across it. It is the difference between homemade and handmade.

Knits (tees, beanies): they stretch, so a plain straight stitch can pop. Use your machine's stretch stitch or a narrow zigzag, and a ballpoint needle.

How flat fabric becomes 3D

Every pattern piece is flat. Seams, darts, curves and folds are how flat pieces wrap around a round body.

• Seams join pieces. A straight seam joins flat to flat. A curved seam makes a shape: the sleeve cap curving into the armhole is what lets your arm move.
• Darts are folded wedges. Sewing a dart takes out fabric at one end and leaves it at the other, so the fabric cups around the seat, the waist or the chest. Our pants use back darts.
• The crotch curve is the deepest curve in clothes. The back curve is longer and deeper than the front because your seat needs more room.
• Pleats and gathers fold or scrunch extra fabric into a smaller edge, like a pleat at the waist or elastic in a casing.
• Ease is the extra room on top of your body measurements. Fitted, regular, relaxed and baggy in step 2 are different amounts of ease.
• Grain is the direction of the threads. The blue arrow on each pattern piece goes parallel to the finished edge of the fabric, so the garment hangs straight and does not twist.

Hand sewing: a button and a patch

Sew on a button

1. Thread a needle with about 24 in of thread, pull it so it is doubled, knot the ends together.
2. Mark the spot. Come up from the back of the fabric so the knot hides behind it.
3. Lay a pin or a toothpick across the top of the button. Sew over it through the holes, 5 or 6 times through each pair (cross or two parallel lines, your call).
4. Pull out the pin. Push the needle up between the button and the fabric, wrap the thread around the stitches under the button 4 or 5 times. That little post is the shank, it gives the buttonhole room.
5. Push the needle to the back, make 3 small stitches in place, knot and cut.

Put on a patch

1. Iron on patch: follow the patch's heat and time. Press with a cloth on top, let it cool. A few stitches around the edge make it last through washing.
2. Sew on patch: pin it or use a dab of fabric glue stick to hold it. Stitch all the way around 1/16 to 1/8 in from the edge, by machine (straight or zigzag over the edge) or by hand.
3. By hand: small whip stitches: come up through the fabric just outside the patch, go down through the patch edge, every 1/8 in. Knot on the back.
4. Patching a hole? Put the patch behind or on top so it overlaps the hole by at least 1/2 in on every side.

How to sew the tricky parts

Patch pocket

1. Fold the top edge down twice and stitch it. That is the opening.
2. Press the other edges under by the seam allowance. Clip the curves so they lie flat.
3. Pin it on the mark. Edge stitch 1/8 in in from the edge, around the sides and bottom.
4. Make a small triangle or backstitch at both top corners. That is where pockets tear.

Centered zipper (bags, skirts, side seams)

1. Sew the seam below the zipper with a normal stitch. Sew the zipper part with your longest stitch (basting). Press the seam open.
2. Lay the zipper face down on the inside, teeth right on the seam. Pin or tape it.
3. Put on the zipper foot. From the outside, stitch down one side about 1/4 in from the seam, across the bottom below the zipper stop, and up the other side.
4. Pick out the basting stitches. The zipper opens.

The zip fly on our pants has its own steps in step 6, How to sew it.

Armholes and sleeves

1. Knits (tees): sew the shoulders first. Lay the shirt open flat. Match the middle of the sleeve top to the shoulder seam, pin the ends, and sew the sleeve in while everything is still flat.
2. Then sew from the sleeve hem, under the arm, down to the bottom hem in one seam on each side.
3. Wovens: sew two rows of long stitches across the top of the sleeve, pull the threads to gather it a little so it fits the armhole smoothly, then sew it in.
4. No sleeve (tanks): finish the armhole with a binding strip: stretch it gently as you sew it on, fold it to the inside and stitch.

Leg openings and hems

1. Wovens: fold up 1/2 in, press, fold up again 1 in, press, stitch near the top fold. That is a double turned hem, no raw edge shows.
2. Knits: fold up once and stitch with a twin needle or stretch stitch so it still stretches.
3. Shorts with elastic legs: zigzag the elastic to the edge on the inside, stretching it as you go, fold it over and stitch again.

Neckbands and collars

1. Rib neckband (tees): our neckband is cut shorter than the neckline (85%) on purpose, so it hugs your neck. Sew the short ends into a loop, fold it in half the long way.
2. Mark the band and the neckline into quarters with pins. Match the pins, stretch the band to fit as you sew.
3. Press the seam toward the shirt and stitch just below it to hold it down.
4. Shirt collars (wovens): iron interfacing on one collar piece, sew the two collar pieces together around the outside, trim and clip the corners, turn it right side out, press, then sew it to the neckline or a collar stand.

Crotch seam

1. Sew both legs first (side seams and inseams). Turn one leg right side out and slide it inside the other, right sides together.
2. Line up the inseams at the bottom of the curve, pin all the way around.
3. Sew from the back waist down around the curve to the front. Sew it a second time right next to the first. This seam takes the most stress of anything you will make.
4. On wovens, clip little cuts into the seam allowance on the tight part of the curve so it lies flat. Finish the edges with zigzag.

Waistbands

1. Button waistband: iron interfacing on the waistband if your fabric is soft. Sew one long edge to the top of the pants, right sides together.
2. Fold the band in half over the seam to the inside, fold the raw edge under, pin.
3. From the outside, stitch along the seam line (stitch in the ditch) or topstitch the band to catch the inside. Buttonhole on the overlap, button on the other side.
4. Elastic casing: fold the casing over, stitch it leaving a 2 in gap, pull the elastic through with a safety pin, overlap the ends 1 in, stitch them, close the gap.

Hat brims

1. Cap brim: two brim pieces of fabric, right sides together. Sew around the outer curve only, trim close, turn right side out, press.
2. Slide in a plastic brim insert. Sew rows of topstitching about 1/4 in apart following the curve.
3. Baste the inside edge closed, then sew it to the front of the crown.
4. Bucket hat brim: two layers (iron interfacing on one for body), sew around the outside, turn, press, then sew rows of topstitching all the way around to stiffen it before sewing it to the crown.

Copy a piece you love (without ripping it apart)

Tracing a garment you already own is called a rub off. You copy each section one at a time.

1. Prep. Wash and press the garment. Lay paper (or a big piece of cardboard you can pin into) on a table.
2. Measure first. Write down the big measurements (chest or waist, length, sleeve). You will use them to check your copy at the end. Or use "Measure a piece you own" and let this tool draft it.
3. One section at a time. Fold the garment in half along the center front. Lay the front section flat on the paper, smooth, not stretched, with the grain (the up and down threads) straight.
4. Mark the seams. Push pins straight down through the seam lines into the paper every inch or so, or run a tracing wheel along the seam. Around curves, place the pins closer.
5. Trace. Lift the garment and connect the pin holes. Mark the center fold, the grain line, notches where pieces meet, pockets and darts.
6. Repeat for the back, the sleeve and every other piece (waistband, pockets, collar).
7. True it up. Smooth the lines with a ruler and a curve. Check that seams that sew together are the same length (walk one edge along the other).
8. Add seam allowance. The lines you traced are the seam lines. Add 3/8 to 5/8 in all the way around for seams, more at hems.
9. Test it. Sew a quick version in cheap fabric before your good fabric. Fix it, then cut the real one.

Copying for yourself is a great way to learn. Do not sell exact copies of another brand's design. Use it as a starting point and make it yours.