If your tee collars keep coming back wavy, stretched, or curling, it is not bad luck, and it is not the fabric being cursed.

It is a small number of spec and sewing variables, and every one of them is controllable.

We run cut‑and‑sew for streetwear brands out of Sialkot, and the neck is where most quality complaints start.

A body can be perfect. Print, sharp. Stitching, clean.

But if the collar ripples or bags out after two washes, the whole tee reads cheap. On a thin single‑jersey tee there is nowhere to hide it.

This is the definitive collar guide. It covers rib choice, attachment tension, taping, curling on thin fabric, self‑fabric vs. rib, neck grading, and QC tolerances.

How to spec all of it in your tech pack so you get the same neck on every unit.

Read it once, spec it once, and stop chasing the same defect.

FLAT — correct tension Rib cut shorter than the neckline, stretched in evenly → gathers & hugs. WAVY — under tension Rib fed with too little stretch → excess neckline length ripples. rib collar neckline edge

The core mechanic. A rib collar is cut shorter than the neckline it joins, then stretched to fit. Get that stretch ratio right and consistent, and the neck lies flat. Feed it slack, and the extra neckline length has nowhere to go it waves.

Chapter 01

Why does the collar tell the tee’s quality?

Pick up any tee and watch what your hands do. They go to the neck.

Buyers pinch the collar, stretch it, and let it snap back before they look at anything else.

It is an instinct, and it is the fastest read on the quality a garment gives.

There is a reason for that. The collar frames the face.

It takes the most abuse pulled over the head every single wear.

And on a lightweight tee, it is often the only part of the garment with any structure at all.

Everything else is a flat single jersey.

The neck is where the making shows.

What does a bad neck signal to a buyer?

  • Wavy / rippled: reads as sloppy sewing. The buyer assumes the rest of the make is rushed too.
  • Stretched / floppy: reads as cheap fabric and no recovery. Kills any premium price point.
  • Curling/rolling: reads as unfinished. Looks like a sample, not a product.
  • Tight / won’t fit over the head: the one defect that generates returns, not just complaints.

Here is the useful part: none of these are random.

Each one traces back to a specific decision: rib, tension, tape, and grading.

Fix the decision, and the defect disappears across the whole run, not one unit at a time.

Chapter 02

Rib type & recovery: 1×1, 2×2, and elastane

Start here, because the wrong rib will defeat perfect sewing every time.

The collar is rarely cut from the body jersey.

It is cut from rib-knit fabric built to stretch and, more importantly, to come back.

1×1 vs 2×2 rib:

The numbers describe the knit structure:

How many stitches face out before the pattern reverses?

  • 1×1 rib: finer, flatter, the standard for most tees. Good stretch, sits close to the body of a lightweight tee.
  • 2×2 rib: chunkier, deeper channels, more elastic, and more visual texture. More common on heavier tees, cuffs, and hoodies. On a thin tee it can look bulky against the jersey.

Neither is “better.” Match the rib weight and gauge to your fabric.

A heavy 2×2 collar on a 140 gsm tee looks bolted on.

A too‑light rib on a heavier tee has no authority and rolls.

Recovery is the word that matters:

Stretch is easy. Any knit stretches.

Recovery is whether it returns to shape after being pulled over a head a few hundred times.

That is what separates a neck that stays crisp from one that bags out across the shoulders.

Recovery comes from two things: fabric and construction.

  • Elastane content: even 2-5% elastane (spandex/Lycra) in the rib transforms recovery. A 100% cotton rib will slowly stretch out and stay stretched. A combed‑cotton rib with a few percent elastane snaps back.
  • Rib weight/gauge: a rib that is too light physically cannot hold the neckline. It needs enough body to resist deformation.

The single cheapest upgrade

If your necks bag out, the first thing to change is the rib composition spec:

A combed cotton/elastane rib instead of 100% cotton. It is a small cost per unit, and it fixes the most expensive‑looking defect.

Chapter 03

Collar attachment tension: why do necks wave?

This is the number‑one cause of the wavy neck, and it is worth reading twice.

The rib collar is cut shorter than the neckline opening it gets sewn into. Not the same length, shorter.

During attachment, the operator stretches the rib slightly so it matches the longer neckline.

That controlled stretch does two jobs:

It gathers the neckline in so the collar hugs, and it puts the rib under just enough tension to lie flat.

Too little tension → waves:

If the operator feeds the rib with too little stretch, the neckline is now longer than the collar is controlling.

That extra length has to go somewhere. It ripples. That is your wave every time.

Too much tension → pucker and tight necks:

Overstretch the rib, and you get the opposite: the neckline puckers, the collar feels tight, and in the worst case, the head won’t go through.

This is the defect that causes returns.

The fix is a ratio, not a feel:

Good factories do not leave this to the operator’s mood.

They specify a collar‑to‑neckline ratio:

The collar is cut to a set percentage of the neckline circumference, commonly around e.g., 85-90%, then attached at a consistent, trained stretch.

On our floor:

  • The rib is cut to spec length, not eyeballed off the roll.
  • Operators are trained to a marked stretch, and the ratio is verified on the first pieces of every run.
  • Differential feed on the overlock is set so the collar and neckline feed evenly, not fighting each other.

Nail the ratio and train to it, and waviness stops being a lottery. It becomes a setting.

Chapter 04

Why do thin‑fabric collars curl (and what are the fixes)?

Curling is a different problem from waving, and it gets blamed on the wrong thing constantly.

Single jersey: the fabric of nearly every tee curls by nature.

It is baked into the knit structure.

A raw jersey edge rolls toward the face at the top and bottom and toward the back at the sides.

This is physics, not a defect. It is why you never leave a jersey edge raw.

So why is the collar itself curling?

When people say “the collar is curling,” they usually mean one of these:

  • The rib is rolling because it is too light to hold its own shape against the neckline.
  • The seam allowance is curling up and pushing the collar out of plane, which is common when nothing is holding it down.
  • Poor recovery: the collar stretched, didn’t come back, and now sits loose enough to fold.

The fixes, in order of impact:

  1. Right rib for the fabric. Enough weight and elastane to hold shape. This alone solves most curl.
  2. Neck tape (next chapter) to stabilize the back neck and enclose the seam allowance.
  3. Correct set tension so the collar isn’t loose enough to roll in the first place.
  4. Coverstitch the seam allowance down. A topstitch that holds the allowance flat against the body kills the roll and reads as a deliberate, premium finish.

If you are wrestling with jersey curl across the whole garment hems and edges, not just the neck, that is a fabric‑behavior topic on its own.

Chapter 05

Shoulder‑to‑shoulder neck taping: the stabilising strip

Flip a well‑made tee inside out and look at the back neck.

There is a clean strip of tape running shoulder to shoulder, covering the seam.

That is neck tape, and it does more work than any other 3 cm of a tee.

What does the tape actually do?

  • Stabilizes the back neck. This is the real job. The back neck is where necks stretch out across the shoulders. The tape stops it. No tape, and gravity plus wear widens the neck over time.
  • Encloses the raw seam allowance for a clean, finished interior with no scratchy exposed overlock against the neck.
  • Signals quality. Buyers have learned to associate visible neck tape with a better‑made garment. It is a premium tell that costs very little.
  • Carries branding. Printed tape is prime real estate for a logo or branding surface; most tees are wasted.

Tape options:

  • Self‑fabric tape: cut from the body jersey. Cleanest, most seamless look; needs to be stable enough not to stretch.
  • Twill tape: the firmest and most stabilizing; classic, slightly more “workwear.”
  • Knit / branded tape: soft and the natural home for printed branding.

For any tee positioned above blank‑commodity pricing, neck tape is not optional.

It is the difference between a neck that holds its shape and one that quietly widens over a season.

Chapter 06

Self‑fabric vs. rib collars: look and behavior

Not every tee wants a rib collar. Some designs call for a self‑fabric neck, the collar cut from the same jersey as the body.

It is a real aesthetic choice with a real trade-off.

  Rib collar Self‑fabric collar
Look Classic tee, defined neckband Minimal, seamless, fashion‑forward
Feel Structured, firmer Softer, more fluid
Recovery Strong (the rib is built for it) A weaker jersey stretches out unless it carries elastane and is set well
Risk Can look bulky on very light fabric Prone to stretch out and roll if under‑spec’d
Best for Every day, durability‑first tees Elevated / minimal designs where the clean neck is the point

The honest read: the rib is the safer, more durable default.

Self‑fabric looks more expensive when it is done right, but it is less forgiving; it demands the good elastane‑blend fabric, tight tension control, and almost always a tape or bound finish to survive.

If a brand wants the clean self‑neck look on a cheap 100% cotton jersey, that neck will stretch out. Tell them before, not after.

Chapter 07

Neck opening size & grading: consistency across sizes

A neck that fits perfectly in a medium and chokes in a small or gapes in an XL is a grading failure, not a sewing one.

The neck opening has to be measured, spec’d, and graded deliberately across the whole size run.

What to define?

  • Neck width (typically measured HPS‑to‑HPS, or across the opening seam to seam).
  • Front neck drop and back neck drop: how low the opening scoops front and back.
  • Neckband/rib width (the finished height of the collar).

Two common grading mistakes:

  • The same neck on every size. Some brands hold the neck constant across sizes for a consistent look. That is a valid choice, but it must be a choice, spec’d on purpose, not an accident.
  • Inconsistent grading. The neck grades a little in some sizes and a lot in others because it was never gradient‑ruled. This is what produces the “fits weird in one size” complaint.

Set your grade rule (hold it, or grade it by a fixed amount per size (commonly a small step like: your grade step, e.g. 0.25″ per size and apply it consistently. Then measure it back in QC (next chapter).

Chapter 08

Collar QC checks & tolerances: what to inspect?

Everything above only holds if you inspect for it.

Here is the collar‑specific QC pass we run fast, repeatable, and tied to numbers, not opinions.

Check How Pass condition
Neck opening Measure flat against spec. Within ± tolerance, e.g., 0.5 cm
Waviness Lay flat, view across the neck. No ripples; the collar sits in a plane.
Recovery Stretch collar, release Returns to shape, no residual stretch
Collar width Measure at several points. Even all the way around
Neck tape Inspect inside. Straight, secure, and fully covers the seam
Stitch quality Inspect seam. No skipped stitches, balanced tension, no pucker

Run this against a proper AQL sampling plan so you are inspecting a statistically meaningful sample, not one lucky piece off the top of the box.

The full inspection workflow, sample sizes, and defect classification live in the QC & AQL inspection guide.

Catch it on piece one:

The cheapest place to catch a collar defect is the first sewn pieces of a run before the whole lot is made wrong.

Verify the collar ratio and neck measurement on the first units every run. It is minutes of work that saves a remake.

Chapter 09

Specifying the collar in your tech pack: the action step

All of this only becomes repeatable when it is written down.

A vague tech pack that says “rib collar” gets you a different neck from every factory and sometimes every run.

Spec it fully and you get the same clean neck every time.

The collar block your tech pack needs:

Spec line Example / what to state
Rib composition Combed cotton elastane
Rib structure 1×1 or 2×2
Finished collar width 2 cm
Collar‑to‑neckline ratio 88% (or state stretch spec)
Neck opening + tolerance Standard
Neck tape Yes/no · material · width · branding
Stitch construction Overlock set + coverstitch topstitch (if used)
SPI 8 to 10 stitches per inch
Callout diagram Measured neck drawing, front + back

Include a measured diagram. Numbers without a drawing get misread; a drawing with numbers does not.

If you want a full walk‑through of building the whole document, not just the collar, see how to write a t‑shirt tech pack.

Spec the collar this tightly once, and the wavy‑neck problem stops being something you chase batch to batch. It becomes a solved line in a document.

Straight answers to the neckline questions brands bring us:

Almost always attachment tension.

The rib collar is cut shorter than the neckline and stretched to fit; if it is fed with too little stretch, the extra neckline length ripples into waves.

Fix it by spec’ing a collar‑to‑neckline ratio and training operators to a consistent, verified stretch.

Poor recovery. A 100% cotton rib stretches over the head and doesn’t fully come back.

Spec a combed‑cotton rib with 2-5% elastane, and add shoulder‑to‑shoulder neck tape to stabilize the back neck.

Together they stop the neck widening over a season.

Usually a rib too light to hold its shape, a seam allowance that isn’t held down, or weak recovery letting the collar go loose.

Fixes, in order: right rib weight, neck tape, correct set tension, and a coverstitch that holds the seam allowance flat.

Rib is the more durable default with stronger recovery.

Self‑fabric looks cleaner and more elevated but stretches out more easily; it needs an elastane‑blend jersey, tight tension control, and usually a tape or bound finish to hold up.

Choose by the look you want and the price you’re building to.

For anything above blank‑commodity pricing, yes.

Tape stabilizes the back neck so it doesn’t widen, encloses the raw seam for a clean interior, and reads as a quality signal.

It costs very little and prevents the most common long‑term neck failure.

Spec it and inspect it. Write the rib composition, collar ratio, neck measurement + tolerance, tape, and stitch construction into your tech pack, then verify the collar ratio and neck measurement on the first pieces of every run against an AQL plan. Once it’s a spec line, it stops being a lottery.

From the T-shirt manual

This is one chapter of The Complete T-Shirt Manufacturing Guides:

These chapters cover taking a T-shirt brand from idea to shipped units, costing, sourcing, tech packs, QC, freight, and launch comparisons. All written from the Sialkot factory floor of Gibben Clothing.

Open The Full T-Shirt Guides

On the floor · Sialkot

Written by

Faizan Ahmad

Chief Apparel Technologist & Head of Manufacturing, Gibben Clothing · Sialkot, Pakistan

Faizan leads production at Gibben Clothing, a cut-and-sew streetwear manufacturer in Sialkot, with 8+ years turning raw yarn into retail-ready hoodies, tees, bottoms, jackets, tracksuits, and headwear. He doesn’t just write about clothing; he works the floor, so every guide here is grounded in real fabric behavior, QC standards, and production data from live runs.