A compression top needs two measurement records: the body range it is designed to fit and the garment dimensions used to manufacture it. Showing only a relaxed chest width leaves the customer guessing, while showing only a body chart leaves production without measurable tolerances.
Define the body chart and the production chart separately
For the body chart, identify chest and waist ranges and any additional dimensions needed for the design, such as upper arm, torso length or neck. Explain where the customer should measure and whether the tape is level and comfortably close. Use the same body definitions in fit recruitment and customer instructions.
For the production chart, define relaxed garment points of measurement, units and tolerances. Show whether widths are flat half-measurements or full circumferences. Add sleeve length, armhole, hem and other relevant points rather than allowing a passing chest width to stand for an approved fit.
Calculate extension without confusing it with reduction
For a simplified circumferential comparison, required extension equals body circumference divided by relaxed garment circumference, minus one. Multiply by 100 to express it as a percentage. This is a planning calculation and does not account for body shape, seams, local tension or pressure.
Hypothetical arithmetic example: a 90 cm relaxed garment circumference fitting a 100 cm body requires approximately 11.1% extension. The garment is 10% smaller than that body circumference, but 10% reduction and 11.1% extension use different denominators. Neither number is a recommended compression specification. Test the real garment and material before approving either.
Match the range to tested material behavior
Check both ends of each intended body range against the actual fabric’s directional behavior, not its maximum advertised stretch. Include the force needed at the relevant extension and the recovery after repeated loading where appropriate. A fabric that can extend far enough may still feel too restrictive or fail to recover suitably.
A larger labelled size does not inherently apply less pressure than a smaller one. Pressure behavior depends on the body, pattern, material and measurement conditions. If quantified compression is claimed, measure the relevant finished sizes using the agreed method instead of extrapolating from a single size.
Recruit wearers at the boundaries as well as the midpoint
Record the dimensions relevant to each wearer’s fit without collecting unnecessary personal information. Test lower, middle and upper positions within the proposed body range and include different proportions. Two wearers with the same chest measurement may differ in waist, shoulder breadth or torso length.
Use a repeatable sequence of reaching, arm rotation, torso bending and the intended sport movement. Check neck comfort, armhole restriction, sleeve pull and hem migration. Stop a trial if the wearer experiences pain, numbness or other concerning discomfort. A sourcing fit session is not a medical assessment.
Size-validation record
Use a row for each wearer and sample version. Keep the body data separate from observations and decisions. Re-run affected checks after changing the pattern, material or edge construction.
| Field | What to record | Why it matters |
|---|---|---|
| Sample identity | Style, size, pattern revision and fabric lot | Links result to reproducible construction |
| Wearer position | Relevant measurements and position in size range | Shows whether boundaries were tested |
| Relaxed garment | Measured dimensions against specification | Distinguishes fit issue from production variation |
| Movement | Action, restriction and garment displacement | Locates the correction rather than just “too tight” |
| Material response | Opacity, seam extension and recovery observations | Finds local limits within the garment |
| After care | Wash procedure and repeated fit outcome | Checks whether the approved range persists |
| Decision | Pass, change or additional trial, with owner | Prevents unresolved sizes from entering bulk |
Publish a size guide that matches the approved evidence
Use body measurements as the customer’s main selection route and explain the intended close fit. Add a between-size instruction only after testing the overlaps and deciding which dimension governs selection. Do not advise every customer simply to size up or down without considering the product.
Retain approved garments for the relevant sizes and connect the chart version to production specifications. If returns cluster at one boundary, investigate measured stock, customer instructions and the grade before changing the entire range. Sports compression sizing supports fit selection; it does not establish a therapeutic pressure level or make the garment a medical device.
