How do I make sure a plus-size range actually fits, instead of remaking it every time?

Three steps. Fit the buyer's core size rather than the middle of the range — on a plus line that is usually 2XL. At confirmation stage, make one sample at each end of the chart and check key points and silhouette only. Then write every correction back into the base pattern and the increment table instead of fixing a single size. Done this way, a plus line normally locks its pattern in two fittings instead of remaking size by size.

Can I just multiply the standard-size grade table to get plus sizes?

No — that is the single most common cause of distortion. Girth grows fast at the plus end while shoulder width barely moves and height changes little, so proportional grading pushes the shoulder point out and lengthens the garment. Workable test: shoulder about 0.6–1.0 cm per size, length 0.5–1.0 cm, armscye depth 0.5–0.8 cm, all clearly below a bust increment of about 5–6 cm. A chart where shoulder grows in proportion to bust can be rejected without fitting anything.

What changes when grading stretch denim for plus sizes?

Two adjustments that pull in opposite directions. Weft recovery absorbs part of the girth, so hip and thigh increments can be trimmed by roughly 0.5–1 cm. But washing shrinks the cloth, so length allowance must be added, and shrinkage has to be measured per wash recipe rather than per fabric. The plus-size hip gain is larger to begin with, so keep seated ease when trimming — otherwise it pulls the moment she sits down.

Why do plus-size hoodies always drop at the shoulder?

Usually because shoulder width was scaled with the bust. Shoulder is skeletal and grows slowly, so once the shoulder point drifts outward the sleeve cap has to lengthen and the garment reads as dropped-shoulder. Fix: hold shoulder at roughly 0.6–1.0 cm per size, give back width its own 0.8–1.2 cm to cover soft tissue, and move shoulder slope whenever armscye depth increases. Fleece thickness also takes another ring of girth, so bust increments need room.

How should I set hip and rise for plus-size stretch knit pants — can I reuse the standard pattern?

Not reuse. Four-way stretch lets you trim hip increments, but the knee must not be graded on woven logic — loosen it and the knee bags while the leg collapses. Rise runs about 0.8–1.2 cm per size and has to be recalculated together with the back crotch curve: too shallow cuts in, too deep droops and pools. The fastest check is one garment in the largest size, worn seated, on stairs and in a squat, watching whether the back crotch drags.

Plus-Size Casual Grading: Fit, Not Scaled-Up

The expensive failures in plus-size casual wear are rarely design failures — they are size failures. A fit sample in M looks perfect, then the 2XL drops at the shoulder, bunches under the arm and folds across the back waist, and the buyer returns the bulk by size. The cause is almost always the same: the grading rules were scaled up from the base size. Girth grows quickly at the plus-size end while height and shoulder width barely move, so multiplying the pattern widens and lengthens a person who did not get taller. This piece stays on the factory floor: how to split increments across four problem zones, how to compensate three casual fabrics, and how to run fit sessions that are fixed in one pass. For the buying-side checklist — grading systems, fabric consumption, minimums — see six sourcing points for plus-size and curve ranges; for the standard-size workflow, see stage three: size grading.

1. Why equal-proportion grading distorts: three physical facts

Multiplying an M by 1.3 does not produce a 2XL. It produces a larger person. Three relationships are what actually need re-drawing:

Girth grows faster than height. Bust may gain 20 cm or more from M to 2XL while height changes by a few centimetres. Armscye depth follows the bust down, but shoulder slope does not, so the sleeve stops hanging — the extra cloth has nowhere to go but the underarm.
Shoulder width grows far more slowly than bust. Shoulder is skeletal; fat distribution barely changes it. Scale it with the bust and the shoulder point drifts outward, the sleeve cap arc has to lengthen, and the garment reads as dropped-shoulder.
The bust point sits lower and dart intake rises. Underbust-to-waist difference is larger at plus sizes, so darts must be reallocated across centre front, side seam and waist. Scale the base-size dart positions and the waistline lands on the hip.

On paper the pattern looks intact; on a body it does not. That is why a plus-size line cannot inherit the standard-size grade table — it needs one rebuilt from the buyer's own chart, which is also why the first thing we ask for on a plus-size enquiry is the size chart, not the sketch.

2. Setting increments in the four problem zones

Plus-size grading is not one set of numbers but a table split by body zone. The ranges below are common for casual categories and are meant to test whether a buyer's chart is internally consistent; actual values follow the buyer's body data and the fit session:

Zone	Per-size increment (typical)	Why not proportional	What goes wrong when over-scaled
Bust	about 5–6 cm	Gain per size is larger at the plus end	Too small: centre front will not close, armscye binds
Waist	about 5–6 cm (may differ from bust)	Waist-to-hip difference often widens	Insufficient darting: folds at back waist, side seam swings forward
Hip	about 5–6 cm	Hip gain usually slightly exceeds bust	Pulls when seated, back crotch drags
Shoulder width	about 0.6–1.0 cm	Skeletal, the slowest dimension	Shoulder point drifts out, cap lengthens, silhouette reads heavy
Back width	about 0.8–1.2 cm	Must cover added soft tissue	Back pulls horizontally, rear armscye binds
Armscye depth	about 0.5–0.8 cm	Must move with slope and bust together	Too deep: underarm pooling; too shallow: cannot raise the arm
Upper arm	about 1.5–2.0 cm	Upper arm gains visibly at plus sizes	Sleeve binds, cuff leaves a mark
Garment length	about 0.5–1.0 cm	Height barely changes, so length must not follow girth	Length drags the figure down, hem flares
Pants: rise	about 0.8–1.2 cm	Linked to hip and back crotch curve	Shallow: cuts in; deep: droops and pools
Pants: thigh / knee	about 2.0–2.5 cm / 1.5–2.0 cm	Thigh gain exceeds knee gain	Leg reads straight-cut by accident, knee bags

One test settles the whole table: shoulder width, garment length and armscye depth must all increment clearly less than girth. A size chart where shoulder width grows in proportion to bust can be rejected without a single fitting.

3. Fabric compensation: one grade table will not serve three cloths

Casual fabrics split into two groups by stretch, and the compensation runs in opposite directions — with stretch you deduct recovery from the increment, without stretch you must leave room for thickness and restriction. This is the step most often skipped:

Fabric	Where stretch comes from	Compensation direction	Watch for
Stretch denim (typically 1–3% elastane)	Weft recovery	Hip and thigh increments can be trimmed; recovery absorbs 0.5–1 cm	Washing shrinks it — add length allowance; measure shrinkage per wash recipe, not per fabric
Brushed fleece (about 280–380 g/m²)	Almost none; ribbing does the holding	Bust increments must be generous — thickness takes another ring	The hem and cuff ribbing stretch ratio decides whether it goes on at all; ribbing should sit one step tighter than the body
Stretch knit pants (ponte, double knit)	Four-way stretch	Hip can be trimmed, knee must not follow woven logic	Over-graded knee bags and the leg collapses
Non-stretch woven casual pants (twill, poplin)	None	Everything comes from the pattern; leave hip increments full	Back crotch curve and rise must be recalculated, never inherited

Denim and fleece also eat grading margin through process: wash shrinkage on denim, pile thickness and ribbing recovery on fleece, so the same pattern produces different fit. Acceptance criteria for those two are covered in denim washes and stretch recipes and in fleece weight and ribbing. The practical rule is one line: settle the cloth, then settle the grade table — change fabric mid-season and the compensation has to be rechecked.

4. Fit sessions: two fittings instead of four remakes

The costliest mistake on a plus-size line is fitting an M and then grading up. An M that fits proves the pattern logic, not the plus-size end. Three steps, in order:

Fit the buyer's core size. On a plus line that is usually 2XL or whichever size carries the most volume. Get the core size right and the line earns its money.
Fit both ends. At confirmation stage, make one garment at each end of the chart, measure key points only, and check whether the silhouette still holds. This is what catches "good in the middle, distorted at the ends" before bulk.
Write corrections back into the rules. Fixing one size fixes one garment; writing the correction into the base pattern and the grade table fixes the line. Every revision should produce three outputs together: the revised base pattern, the updated increment table, and fit photos marked with the change points.

Fit records are also the basis for re-orders. If a re-order changes fabric mill or wash house, re-verify shrinkage and recovery before touching increments; skip that and the complaint becomes "same pattern, different hand feel".

5. Pre-order checklist

Get the buyer's size chart and check that shoulder, length and armscye increments are smaller than girth increments;
Confirm whether the chart is body measurements or garment measurements — mixing them shifts the whole line by one size;
Split the grade table by fabric: trim where there is stretch, leave room where there is none, and recheck fleece and denim separately;
Fit the buyer's core size, not the middle of the range;
Make one confirmation sample at each end of the chart and check key points and silhouette only;
Deliver the revision trio — base pattern, increment table, fit photos — not just a pattern file;
Inspect bulk on the largest size first: if the largest size passes, the middle sizes almost always will.

How LIUYU handles plus-size casual orders: we grade from the buyer's own size chart rather than forcing one universal increment table onto every client. Sampling takes 3–5 days and bulk 10–20 days, with an MOQ of about 50 pieces per style — enough to run one style at the plus end before committing a season. We are a team of 80+ founded in 2014, and have served 307 clients across 59 countries, a good share of them on Western casual and modest lines where plus sizes and longline shapes are routine work rather than an occasional category. Send sketches and a size chart and we will come back with an increment proposal and a recommended fit size.

Plus-size grading is not enlargement, it is reallocation: give the girth increase to the zones that need it, and hold the zones that do not — shoulder width and length above all. Do that and the same sketch keeps its original silhouette at the plus end.

Frequently asked

How do I make sure a plus-size range actually fits, instead of remaking it every time?: Three steps. Fit the buyer's core size rather than the middle of the range — on a plus line that is usually 2XL. At confirmation stage, make one sample at each end of the chart and check key points and silhouette only. Then write every correction back into the base pattern and the increment table instead of fixing a single size. Done this way, a plus line normally locks its pattern in two fittings instead of remaking size by size.
Can I just multiply the standard-size grade table to get plus sizes?: No — that is the single most common cause of distortion. Girth grows fast at the plus end while shoulder width barely moves and height changes little, so proportional grading pushes the shoulder point out and lengthens the garment. Workable test: shoulder about 0.6–1.0 cm per size, length 0.5–1.0 cm, armscye depth 0.5–0.8 cm, all clearly below a bust increment of about 5–6 cm. A chart where shoulder grows in proportion to bust can be rejected without fitting anything.
What changes when grading stretch denim for plus sizes?: Two adjustments that pull in opposite directions. Weft recovery absorbs part of the girth, so hip and thigh increments can be trimmed by roughly 0.5–1 cm. But washing shrinks the cloth, so length allowance must be added, and shrinkage has to be measured per wash recipe rather than per fabric. The plus-size hip gain is larger to begin with, so keep seated ease when trimming — otherwise it pulls the moment she sits down.
Why do plus-size hoodies always drop at the shoulder?: Usually because shoulder width was scaled with the bust. Shoulder is skeletal and grows slowly, so once the shoulder point drifts outward the sleeve cap has to lengthen and the garment reads as dropped-shoulder. Fix: hold shoulder at roughly 0.6–1.0 cm per size, give back width its own 0.8–1.2 cm to cover soft tissue, and move shoulder slope whenever armscye depth increases. Fleece thickness also takes another ring of girth, so bust increments need room.
How should I set hip and rise for plus-size stretch knit pants — can I reuse the standard pattern?: Not reuse. Four-way stretch lets you trim hip increments, but the knee must not be graded on woven logic — loosen it and the knee bags while the leg collapses. Rise runs about 0.8–1.2 cm per size and has to be recalculated together with the back crotch curve: too shallow cuts in, too deep droops and pools. The fastest check is one garment in the largest size, worn seated, on stairs and in a squat, watching whether the back crotch drags.