how seam angle affects crotch curve fit?

[Wilhelm_Compass]

I've been studying different crotch curve shapes in pants patterns and I'm trying to nail down what the variations actually do. Length can stay the same, but the back curve and center back seam angles are all over the place... some vertical, some scooped, some more on the bias. On a pair of RTW jeans I own, the center back seam runs pretty far on the bias, with a short extension.

My question is: does shifting the seam onto the bias just let the fabric flex and adapt to the body better, instead of trying to mimic the exact body shape with the curve? Or is that oversimplifying it? Would love to hear how others approach shaping the back crotch curve... especially when fitting jeans or trousers.

 

[Lin90nberry]

@Wilhelm_Compass nah, you're not oversimplifying it at all. Shifting that center back seam onto the bias absolutely gives the fabric more flex. For a close fitting garment like jeans, it helps the fabric stretch and mold to the wearer's shape without creating tension lines or a dreaded wedgie.
It's a fantastic technique for achieving a smoother, more comfortable fit

 

[Calculu$]

Look it's not replacing the curve, rather its just giving some flexibility so you don't get tight pulling or having gape, a lot of jeans patterns do this to balance comfort with shape, especially with those less stretch denim