I’ve sewn 1920s peach tap pants. I’ve used rayon/ viscose fabric which was used for underwear in the 1920s.
The tap pants are closed on the side with two buttons, like these 1920s tap pants.
Here you see the continuous bound placket.
The side seams I’ve finished with french seams, like these 1920s tap pants.
I’ve joined the crotch piece with a flat felled seam, and finished the bottom of the tap pants with a narrow hem, as on these 1920s tap pants.