From the first size to perfect fit
Size grading is not a mathematical scale.
Size grading is not a mathematical scale.
Size grading is not a mathematical operation. It is not a matter of multiplying the base size measurements by a coefficient: it is a matter of maintaining the garment's balance across different bodies, preserving the visual proportions and the fit that define the brand. A skirt that hangs well in a size 38 must hang equally well in a size 46 — but with linear grading, it almost never does.
Atelier ModArch handles size grading as an integral part of the pattern-making process, not as a downstream operation. This means that grading points are defined while building the base pattern, in relation to the garment's structure and the brand's production requirements.
Grading is the process of increasing or decreasing the base pattern to obtain all sizes in the range. Grading points — the points on the pattern that shift during the process — are not identical for every garment: they change with the garment type, the fabric, and the brand's reference body. A tailored dress grades differently from a technical outerwear piece. A stretch garment behaves differently from a structured one.
For complex garments, fitting cannot be separated from size grading. We check critical sizes on a graded dress form and, when needed, on a live fit model. Corrections are recorded directly in the CAD file. See also our standalone Fitting service.
Three variables weigh more than any others: the number of sizes in the final range, the number of pieces in the pattern (a technical outerwear piece with 20-28 pieces requires far more work than a garment with 12), and the method of execution — CAD grading is faster and more repeatable than manual grading, with on-screen verification of every size. How these variables affect the grading work is detailed in the guide how much pattern making costs. Grading is quoted separately from the construction of the base pattern precisely because it depends on different factors.
In the studio's method, size grading starts only once the base size has been approved in fitting. The reason is arithmetic: a defect in the base propagates to every size in the range, often amplifying at the extremes. Fixing the base first — with defect correction if the pattern comes from a third party — costs a fraction of what correcting the entire graded range would cost. After grading, the next step towards production is marker making: the optimised layout of the pieces of all sizes on the fabric.
It depends on the brand. The most common ranges in luxury are 5–7 sizes (e.g. 36–48 or XS–XL). We handle wider ranges (up to 12 sizes) for brands covering extended market segments or for sportswear with extended sizing.
Yes. Children's grading follows different proportional rules from adults' — body proportions change significantly between sizes. We handle ranges from 0 to 14 years with proportional control specific to each age band.
A validated base pattern in the sample size (native CAD file or DXF), the brand's official measurement chart (if it exists) or reference for the required ranges, and a physical sample garment if available. If no measurement chart exists, we can build one together starting from the brand's target.
Yes, but we advise against it for complex garments. Size grading without a fitting check on at least one critical size can lead to problems that only surface in production, where they cost much more to fix.