An approved sample in the base size confirms the fit of the style in that particular size. It does not guarantee that the same style will fit equally well in XS and XXL. As the size changes, the proportions of the pattern pieces and support requirements also change, and simply scaling the outlines up or down may not be enough.
What Is Size Grading?
Size grading is the process of increasing or decreasing base patterns using defined increments at specific points. It creates the patterns required for the planned size range.
For bras, both the underbust measurement and cup size need to be considered. The cup height and width, side panel length, and strap position are checked. The band width and elastic specifications may also need to be adjusted.
An issue in the base pattern can carry over into other sizes, while unsuitable grading increments may become particularly noticeable at the ends of the size range. During fittings, this can appear as cup distortion, insufficient support, edges digging into the body, or fabric creasing.
Why Do Sizes at the Ends of the Range Behave Differently?
Excess fabric and excessive tension can affect fit in any size. At the same time, larger bra sizes may have greater support requirements, making it important to check how the band, side panels, and straps perform under load.
For swimwear, the fit should also be evaluated after the garment becomes wet and during movement. The same style in size M and XL may require different construction solutions to maintain a secure fit and adequate support.
The Role of Additional Fittings
After grading, it is advisable to check several sizes, including those at the ends of the planned range. The number of sizes to be tested should be agreed based on the garment construction and the width of the size range.
During fittings, the position of seams, cup depth, elastic tension, and garment stability during movement are evaluated. If necessary, individual pattern areas, elastic specifications, or support elements are adjusted. These changes help account for the requirements of specific sizes.
What Should Be Finalized Before Production?
Before bulk production begins, the size range, grading rules, finished garment measurement chart, and acceptable tolerances should be agreed. The documentation should also record the approved materials and any changes made following fittings.
It is important that all approved changes are incorporated into the working patterns and technical files. If you are planning a broad size range, we can discuss it during the development stage to determine in advance which sizes should be tested.
