How to Grade Sewing Patterns for Production Runs

Grading (or scaling) a sewing pattern means applying a set increment from a table to every point of the base pattern, to generate the other sizes without losing the shape or balance of the piece. Bust or chest circumference grows more between sizes than length does, and each point has its own shift distance. It is done by hand with a ruler and a square along guide lines, or just once in a CAD program that then generates the whole size range.

Modeltex production guide. Updated on Sep 8, 2026.

What grading a sewing pattern means

Grading a pattern (also called scaling) is generating the larger and smaller sizes of the range from a base pattern, moving each point of the piece the distance given by an increment table. It is not enlarging the drawing by the same proportion: the body does not grow equally in every direction, and each point (armhole, neckline, side seam) has its own shift.

The base pattern is usually a middle size, for example M in women's sizes or 40 in men's sizes. The goal is not just to make the garment fit another body, but to keep the same balance and the same relationship between pieces in every size, and to make sure the pieces that are sewn together still match up.

The increment table: how much each measurement grows per size

The increment table states, for each key measurement of the garment, how many centimeters it grows or shrinks from one size to the next. It comes from the size chart of the brand or of the market the style is aimed at, and it changes for women, men or kids and for each type of garment.

As a rough reference (it varies with each size chart), bust or chest circumference usually grows 4 to 6 cm per size, waist and hip in similar proportions, and total length only 1 to 2 cm. At the ends of the size range (3XL, 4XL) the circumference usually grows faster, because the body increases more in circumference than in height.

Manual method: grading by hand with a ruler and a square

It is done on the paper base pattern, first drawing horizontal and vertical guide lines (bust line or hip line, center front) that act as a fixed reference for moving each point of the outline.

From those lines each point is shifted the distance given by the increment table, using a ruler and a square to keep the right angle, and the new points are joined with a French curve or a hip curve. It is accurate if done carefully, but repeating it across eight or nine sizes for every piece multiplies the work and the risk of error.

CAD method: Optitex, Audaces, Gerber

In a garment design program, grading is entered just once per piece: horizontal and vertical growth rules are assigned to each point of the outline, and the system automatically generates the rest of the sizes in the range.

The advantage is that it keeps the same criteria across all the pieces of the style at once, lets you review the nested sizes on screen and exports directly to DXF/AAMA, PDS or ADS, the format later used by a computerized marker. But if the increment table you enter is poorly thought out, the mistake is repeated just as fast across all eight sizes.

Common mistakes when grading by hand

The most frequent one is losing alignment: if the guide lines are not properly fixed before the points are moved, each new size drifts a little from the previous one and the piece loses its proportions, which shows most on darts, openings or pockets placed precisely.

The second is not keeping the notch point aligned between sizes: the notch that marks where a sleeve enters the armhole, or where a collar meets the neckline, has to move by the same rule as the rest of the outline. If it is marked by eye on each size, the pieces match in some sizes and are off in others, and that is only discovered when sewing.

How to check that grading came out right

First, compare the growth between consecutive sizes: measure the same line (bust, waist, length) on every size of the range and check that the difference from the previous one is what the increment table says, no more and no less.

Second, and just as important, check that the pieces sewn together still match up in every size: the front armhole with the sleeve cap, the collar with the neckline, the front side seam with the back one. The final check is to sew the base size and one of the extremes, fit them and correct the table if the fit has changed.

The alternative: start from a pattern with the size range already graded

Grading each style, checking it size by size and sewing samples at the extremes is real work that has to be done to launch your own design, and it is worth understanding even if you later delegate it. But to produce without developing new patterns for every launch, you can skip that development by starting from a pattern that already has the size range solved.

Modeltex digital patterns come with the full size range already graded and approved with a sewn sample (eight sizes for adults, XS to 4XL, and nine for kids, 2 to 18), as PDF to print or as DXF/AAMA, PDS and ADS files to load straight into Optitex, Audaces or Gerber. It is the option for not repeating the grading and checking on every new style you add to your own catalog.

Frequently asked questions

How do you grade sewing patterns?

Grading a pattern means moving each point of the base pattern the distance given by an increment table, following horizontal and vertical guide lines, to generate the other sizes without losing the shape of the piece. It is done by hand, with a ruler and a square on the paper pattern, point by point, or in a CAD program such as Optitex, Audaces or Gerber, which loads the table once and generates the whole size range automatically.

What is a grading increment table in patternmaking?

It is the table that states how many centimeters each key measurement of the garment (bust or chest, waist, hip, length) grows or shrinks from one size to the next, split across the pieces and points of the pattern. It comes from the size chart of the brand or of the market the style is aimed at, and it is the basis of grading, both by hand and in CAD.

How much does a pattern grow from one size to the next?

As a rough reference, bust or chest circumference grows 4 to 6 cm per size, waist and hip in similar proportions, and total length only 1 to 2 cm, although the exact number depends on each brand's size chart. At the ends of the size range (3XL, 4XL) the circumference usually grows faster, because the body increases more in circumference than in height.

Can you grade a pattern by enlarging it on a photocopier or as an image?

Not reliably. That method enlarges the whole drawing by the same proportion, and the body does not grow that way: circumference grows considerably more than length. A garment graded by percentage tends to come out too long, with a distorted armhole or neckline; the clean way is to apply the increment table point by point, by hand or in a CAD program.

What is the difference between grading a pattern by hand and in CAD?

By hand it is repeated point by point and size by size on the paper pattern, with a ruler and a square: accurate, but slow and with more risk of error as the number of sizes grows. In a CAD program such as Optitex, Audaces or Gerber the increment table is entered just once per piece and the system generates the whole size range, ready to export as DXF/AAMA.

What is a notch point and why does it matter when grading?

It is the notch that marks where two pieces have to match when sewing, for example where the sleeve enters the armhole or where the collar joins the neckline. When grading, that point has to move by the same rule as the rest of the outline; if it is placed by eye on each size, the mismatch is only noticed on the sewing line.

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Sewing patterns ready for production, with the full size range, in the Modeltex catalog.