How to select clothes that are certain to make you look slender is the most important knowledge a modern woman can have. Surely it is the most important art in the whole field of fashion. And yet, many designers of clothes for stout women do not understand its very cardinal principles. Of course, they do design so-called “slenderizing stouts”—but you know, perhaps all too well, what they look like. Their long surplice effects and drab colors say as plainly as words, “I am designed for a stout” and nine times out of ten they simply call attention to your stoutness. Besides they are for matronly women—not for those who want to look young and smart. It seems practically impossible to get youthful and appropriate clothes for women who wear sizes over 38. Yet it may be only necessary to change a neckline or remove an ornament or alter the line of a sleeve in order to transform a “dumpy fat woman’s dress” into a model of slender grace and youthful charm.

The whole art rests upon a certain scientific principle known to artists and a few expert designers. It is called the Principle of Optical Illusion, by which things appear to the eye to be different than they really are. By understanding and properly using this principle, objects may be made to appear larger or smaller, taller or shorter. And by employing this principle in dress any woman can be made to look older or younger, shorter or taller, stouter or slenderer than she actually is.

For example, just as white shoes make large feet look much larger, so do certain lines and colors make a large figure look a great deal larger, while correct lines and colors and subtle touches give the effect of slenderness, youth and grace.

Every stout woman has, some time in her experience, come by chance upon a dress which seemed to make her look more slender and younger, and she has worn and worn that dress almost to shreds, hating to part with it because there was no telling when she would find another one to give that same effect.

But there is no reason why you should trust to chance in selecting becoming clothes. For if you know this simple yet all important principle of optical illusion, you can plan or make or select every item of your wardrobe with the certain knowledge that it will have a slenderizing effect on your appearance.

You can know beforehand that every dress, every coat, every hat, every garment you wear will be designed to give you height instead of width, youth instead of matronliness, slenderness and grace instead of heaviness. It doesn’t matter whether you buy your clothes ready made, have them made by a dressmaker, or make them yourself—you can always know just what to select to make your particular type of figure look as slim and well proportioned as possible.

The two vertical lines are exactly the same length—measure them and see. Short lines turned back at either end make one seem short; extended lines make the other seem longer.

These two illusions are almost duplicated in the dresses above. As a result one woman looks shorter and heavier, the other taller and slenderer than she really is.