Roomy fit needs balanced proportions
Simply choosing a larger regular T-shirt does not necessarily create the oversized silhouette you want. The body may become too long, the neckline may feel wrong, or the sleeve and shoulder proportions may lose balance. The development target is an overall shape, not a size label.
Review shoulder width, chest width, body length, sleeve length and sleeve opening together. The shoulder position affects the upper-body line, chest width creates space, and body length helps determine whether the result reads as short and boxy or long and relaxed.
Translate the reference into measurements
A model photograph communicates a visual direction, but it is not a complete production specification. Camera angle, model height, garment size and posture influence the impression. Add information about the target wearer and the important dimensions.
If a physical reference is available, measure it using an agreed method and identify what to retain or change. “As loose as the picture” is difficult to assess consistently. A written measurement brief gives both sides something more precise to discuss.
Fabric helps create the silhouette
The same pattern can behave differently in different materials. A fabric with more body and a softer, fluid fabric will form different shoulder, sleeve and torso lines. Fit approval is most informative when the sample uses material close to the intended production choice.
After approving the base size, review how the other sizes develop. An oversized design does not mean increasing every measurement by the same amount. Use the size chart, measurement instructions and fitting feedback together to keep the design consistent across the range.