My sail is older, no identifying labels, tanbark & feels kind of stiff. The lines in the sail edges are heavier than I've seen and it's like the sail cloth has "molded" to the rope, you see the twists. The sail is puckered along the luff line. Is this a design or is the sail flawed?
Your description is of a very old or very expensive 'off-shore' sail if of recent manufacture.
The 'molding' is because of the massive amount of 'hand-sewing' the 'rope' directly to the sail with stout 'sail twine' which is pulled very tight per stitch ... thus the 'little twists'. Nowadays such rope is cheaply inserted into a machine sewn sleeve .... or instead of luff-rope, several overlays of 'sail tape' with no 'rope' at all.
What you describe is a 'work of art' and super-expensive ... if its still in 'good' shape. The sail you have should be VERY stable in its dimensions and usually doesnt suffer the the normal 'shrinkages' of modern sails. Such 'heavy' sails are usually seen on boats that make long distance ocean passages or that circumnavigate.