These dresses, which have long sleeves and high necklines, are perfect for small, informal dinners. They are not sufficiently formal for the more dressy occasions. Most of us, though, rarely wear the diamond-tiara type of clothes and hate to put our whole evening dress investment into one dress we can seldom wear. The solution is a plain, well-cut evening gown with a matching jacket which can be made more or less formal by the jewelry one wears. Even if it's cut quite low, it's appropriate to wear when the men are in black tie, yet its simple ele­gance lets it go with grace wherever people are exceedingly dressy. If you have only one evening dress, your best choice of color is black. Peo­ple don't remember they've seen you in it again and again as they do a frock of an unforgettable color, however becoming. A famous dress de­signer once told me that men always admire most the black evening dresses in her collections, especially if they have lace on them. This may be a hint for you to remember when you're choosing a dress.

is it their clothes ?
Before you give a dinner party at home and suggest that your guests "dress," be sure you want formality, especially since many people will have to refuse because they don't own evening clothes and are unwill­ing to buy them for this one occasion. These days, if a hostess invites guests to an informal dinner, women usually wear what are known as "afternoon dresses" and the men, business suits.

for dining informally
There's a bit more leeway in the sort of informal dress you buy with a dinner party in mind, than there is in the evening dress department. Again, a basic black dress is very useful because there are so many ways to make it seem different by adding or subtracting a scarf, a belt, costume jewelry. Usually, however, one is able to own at least two dinner dresses. The second can be a print, a brilliant or pastel color for a change from the basic black.

whether or not you're the cook
What the hostess should wear when she entertains is an even more interesting question, particularly if she is also the cook. If you have help in the kitchen for a party, you can wear anything you like within reason. Hostess gowns are beautiful, comfortable, and a great inven­tion. The hostess can properly wear one of these, even if the other women wear short skirts and the men, business suits. If you are your own cook, however, a hostess gown is a foolish choice. It will get in your way, even if all you have to do after you dress is serve the food.