The practical difference
A slim fashion cut and a jacket intended for layering need different ease. Leather may soften with wear, but a jacket that restricts breathing or arm movement is not the right starting fit.

Comparison guide
The correct jacket size is determined by shoulder position, chest comfort, sleeve length and movement—not only the number on the label. Cuts vary between brands and models.
A slim fashion cut and a jacket intended for layering need different ease. Leather may soften with wear, but a jacket that restricts breathing or arm movement is not the right starting fit.
Check the shoulder seam, close every fastening, raise and cross your arms, sit down and test the pockets. Repeat the fitting with the layer you normally expect to wear underneath.
Choose the size that keeps the shoulders clean and allows normal movement without excess fabric. Sleeve or waist adjustments may be possible, but the basic shoulder structure should already be correct.
Five checks before deciding
Material grade, construction, size and current availability must be evaluated on the exact item. Final details and prices are confirmed in store.