Some time ago I bought this great out-of-print book on Amazon:
Kenneth, Frances. Secrets of the Couturiers. New York: Exeter, 1984. Print
So yesterday, reading the chapter on Dior, I came across his quote on grainline marking. (By the way, it is amazing, sometimes you just happen to come across specific information just when you are interested in it most):
"To facilitate the fittings, the dresses arrive at the studio entirely covered with guide threads. Those threads, in contrasting colours that show up clearly against the material, have been sewed through every one of the pieces that make up a dress. One follows the grain of the material, and the other is at right angles to it [crossgrain marking, a-ha!!!]. The bias lies between the two. The guide threads, pitiless critics, reveal all the possible faults in the cut, and must find points of equilibrium in essential parts of the dress."
It sounds almost poetic dear readers, doesn't it? After reading this chapter I made connection with what i saw in men's bespoke tailoring where all jackets were meticulously marked for grainlines. And Dior used tailoring techniques to the extreme. Back to Shaeffer again, many of her Custom Couture patterns apply classical men's tailoring techniques. A whole new chapter...