Which merchandise contributes highest dollar volume to Christmas sales in most department stores: toys? giftware? children's apparel? lingerie? None of these. It's menswear, and not just the traditional neckties, either. The Christmastime sales for dad, brother, and son run right across men's wearables and include robes, sweaters, slacks, shirts, shoes, belts, ties, grooming accessories, jackets, coats, caps, scarfs, socks, cologne - even new underwear. Surveys show most of these are bought by women shoppers from family gift lists. Merchants say they believe this is the main way the American male gets most of the yearly additions to his wardrobe.
''What we do,'' says one West Coast merchandiser, ''is buy our holiday lines in depth every year - usually in one big purchase for fall arrival - and then get these goods out on display early. Budgeting to buy these menswear stocks isn't all that difficult. The same general type of goods sells well every year, as a rule - new style gimmicks notwithstanding.''
Merchants selling menswear say the greatest problem at Christmastime is finding out a man's size for clothing. Consultants say shoppers would do well to pay attention to the details of men's size ranges when running down that Christmas list. Some common areas:
Shirts. Most now come in combination sleeve lengths. Example: Size 15 neck will have 32-33 (inch) sleeves. To determine a wearer's sleeve preference, measure a favorite shirt from the center of back collar to tip of cuff. Material is important, too. Eighty percent polyester can be ''hot,'' whereas more cotton content will offer a cooler-breathing garment.
Socks. Men's socks - color and weave aside - are now offered mostly in one-size stretch nylon. Shoppers need to know if the gift-getter likes short-shorts, calf-height, or over-the-calf lengths - not to mention reinforced toe-and-heels.
Slacks. The waist measure is easy for a buyer; it's the leg length to watch. If the gift-getter wears a 29-inch length, then a 30-31 is too long - no matter how much he says he likes the style, cut, and color on Christmas morning.