This page is for a domestic buyer, a pattern maker, a CAD operator, or anyone who needs to understand how grading works once a pattern is digital. This lesson mainly teaches the product flow: turning one base-size digital pattern into a complete, correctly-scaled size run.
Cedar & Co., a domestic brand with 12 shops sourcing on open account from Delta Garments, holds its own T-shirt style CC-114 as a digitized base pattern in size M. A buyer new to CAD grading tends to assume each size still needs its own separate drawing. In fact a CAD system applies one fixed grade rule to the base pattern automatically, producing every other size from the same digital file, in seconds rather than the hours manual grading with rulers would take.
You need: lesson T25-C01-L02 is useful background but not required. A basic idea of what a grade rule is enough to start; Cedar & Co.'s own illustrative size-run figures are given in full below.
By the end of this lesson you can:
Not covered here: digitizing a paper pattern (lesson T25-C01-L02), building a digital marker from a graded pattern (lesson T25-C01-L04), and assembling a complete CAD pattern and marker worksheet (lesson T25-C01-L05).
| Term | Meaning |
|---|---|
| Grading | Scaling a base pattern up or down to produce every size in a size range, following a fixed grade rule. |
| Grade rule | The set amount added or removed at each specific point on a pattern, for each size step away from the base size. |
| Base size | The size a grade rule is applied to as the starting point for producing every other size in the range. |
| Size run | The complete set of sizes a style is produced in, such as S, M, L and XL. |
| Multi-size marker (ratio marker) | A marker containing pattern pieces for several sizes together, laid out in the order's own size ratio. |
| Nested marker | A marker whose pieces are arranged tightly, odd-shaped pieces fitted into each other's gaps, to reduce unused fabric between them. |
| Grading rules | The tech pack section stating the base size and the grade rule applied to produce every other size in the range. |
Grading scales a base-size pattern up or down to produce every other size in a range. In a CAD system, a pattern maker sets a grade rule once, a fixed amount added or removed at each point of measure for each size step away from the base size, and the software applies that same rule automatically to generate every size. A person still decides what the grade rule itself should be; the CAD system only carries out the repeated scaling calculation across the whole size run once that decision is made.
| What can differ | The shapes you will meet | Why it matters |
|---|---|---|
| A domestic Make to Stock style graded across four sizes | Cedar & Co.'s own style CC-114 is graded S, M, L, XL from a size M base pattern, using a fixed grade rule Cedar & Co.'s own pattern maker set once. | A domestic brand reordering the same style every season regrades nothing after the first setup; the CAD system reapplies the same saved grade rule to every future cutting run. |
| An export order graded across a wider size run | Order A's own T-shirt is graded S, M, L, XL from a size M base pattern using its own fixed grade rule, matching the order's own size ratio of 1:2:2:1. | A wider size run, or one with extreme sizes far from the base, tests whether a single fixed grade rule still produces a sensible fit at every size, since garments do not always scale in perfect proportion. |
| A style with different grade rules at different points of measure | A point such as sleeve width may carry a smaller grade increment per size step than body length, since a sleeve fits differently than a torso does as sizes grow. | Applying one single grade increment to every point of measure, instead of the correct value for each point, produces a garment that grows unevenly and fits worse at the sizes furthest from the base. |
| Grading a style with no prior paper history, drafted directly in CAD | A new Cedar & Co. style is drafted directly in a CAD system, with a grade rule set by the pattern maker from experience with similar past styles, since no paper grading history exists to check it against. | A brand-new grade rule carries more risk of being wrong at first use, since there is no prior paper sample at other sizes to compare the digital result against before cutting a size run. |
Cedar & Co.'s own pattern maker sets a grade rule for style CC-114: body length changes 2 cm per size step, half chest changes 2.5 cm per size step, sleeve length changes 1 cm per size step. Starting from the base size M, digitized at body length 72 cm, half chest 53 cm and sleeve length 22 cm, the CAD system applies this grade rule automatically to produce sizes S and L directly, then L to XL by the same increment again, without the pattern maker drawing any of those three sizes separately.
A pattern maker never needs to draw size XL separately to know its own half chest measurement; the grade rule and the number of size steps from the base size are enough to calculate it directly, and the CAD system applies the identical calculation to every point of measure on every pattern piece at once.
The methodA common mistake is assuming that if a fit problem shows up in one size, only that size's own pattern needs correcting. Since every size in a CAD-graded run comes from the same base pattern and the same grade rule, a wrong grade rule at one point of measure affects every size that point applies to, not just the size where someone happened to notice the problem. What this costs Cedar & Co. is real: if the sleeve length grade rule is set at 1.5 cm per step instead of the correct 1 cm, sizes S, L and XL all carry the same sleeve-length error relative to the approved base size M, not only the one size a shop customer happened to return.
Grading takes one pattern, drawn in one size, and scales it up or down to make every other size a style needs. In a CAD system, a person sets one fixed rule for how much each measurement point should grow or shrink at each size step away from the base size, and the software applies that same rule to produce every size automatically. Nobody draws size small or size extra-large separately; the software calculates each one from the base pattern and the rule. This is faster than drawing every size by hand, but it means a wrong rule affects every size at once, since they all come from the same starting pattern and the same calculation.
A Cedar & Co. shop reports that several size L customers find style CC-114's own sleeve short. Omar, the owner, asks the pattern maker to look into it. The pattern maker opens the CAD file, adjusts size L's own sleeve length pattern piece directly on screen, lengthens it by 1.5 cm, and reports the fix as complete.
Here is the message the pattern maker sends to Omar:
Does adjusting only size L's own pattern piece resolve the underlying problem? Decide before opening the answer.
No, adjusting only size L's own pattern piece does not resolve the underlying problem if the sleeve length grade rule itself is wrong. Two facts missing from the pattern maker's message decide this.
First, if size L's own sleeve is short because the grade rule between M and L understates sleeve growth, then size XL, graded from the same rule one more step out, is short by an even larger amount, and this fix does not touch size XL at all. Editing one size's own pattern piece directly, rather than the grade rule that produced it, leaves every other affected size unchanged.
Second, a direct edit to size L's own pattern piece breaks the fixed relationship between the base size and every graded size, since size L's own sleeve pattern no longer follows the same grade rule as the rest of the range. Future regrading from the base pattern would silently overwrite this manual fix, since the CAD system has no record that size L was edited outside the normal grade rule.
The corrected fix should check the sleeve length grade rule itself against the base size's own approved measurement, correct the rule if it is wrong, and regenerate every size, not edit size L's own pattern piece in isolation.
Using Cedar & Co.'s own illustrative figures for style CC-114:
Fixing one reported size while leaving its own grade rule wrong means roughly half of Cedar & Co.'s next reorder of style CC-114 is still cut to the same sleeve-length error, simply in sizes where no customer has complained yet.
Open the course workbook's "Grading check" sheet. It lists a style's own base size point of measure, its grade rule per size step, and calculates each other size's own resulting value automatically, so a pattern maker can confirm the CAD system's own output before trusting it for cutting. Enter a different style's own base measurements and grade rule to see how the same calculation applies.
[Download the CAD pattern and marker worksheet](../../templates/T25-C01-cad-pattern-and-marker-worksheet.xlsx)
1. Cedar & Co.'s own style CC-114 has a base size M body length of 72 cm and a grade rule of +2 cm per size step. What is size S's own body length, one size step below the base?
2. A shop reports a fit problem only in one size of a CAD-graded style. What does this most likely indicate about where the correction should happen?
| EN | AR | FR | TR | Meaning |
|---|---|---|---|---|
| Grading | التدريج | Gradation | Gradasyon | Scaling a base pattern up or down to produce every size in a size range, following a fixed grade rule. |
| Grade rule | قاعدة التدريج | Règle de gradation | Gradasyon kuralı | The set amount added or removed at each specific point on a pattern, for each size step away from the base size. |
| Base size | المقاس الأساسي | Taille de base | Temel beden | The size a grade rule is applied to as the starting point for producing every other size in the range. |
| Size run | مجموعة المقاسات | Gamme de tailles | Beden aralığı | The complete set of sizes a style is produced in, such as S, M, L and XL. |
| Multi-size marker (ratio marker) | ماركر متعدد المقاسات (بنسبة) | Placement multi-tailles (au ratio) | Çok bedenli pastal (oranlı) | A marker containing pattern pieces for several sizes together, laid out in the order's own size ratio. |
| Nested marker | ماركر متعشِّق القطع | Placement avec emboîtement (nesting) | İç içe yerleştirilmiş pastal | A marker whose pieces are arranged tightly, odd-shaped pieces fitted into each other's gaps, to reduce unused fabric between them. |
| Grading rules | قواعد التدريج | Règles de gradation | Gradasyon kuralları | The tech pack section stating the base size and the grade rule applied to produce every other size in the range. |
You now know how a CAD system grades a digital pattern across a full size run from one base size. The next lesson takes that graded pattern and shows how a CAD system builds a marker that hits a target fabric consumption before cutting begins. Back to the course map