Menswear designers will walk a narrow line, and a broad one, in their spring collections should warm weather ever return. When designers aren't sure how to make something look different for the season ahead, they simply take out the ruler and start striping.

Stripes have become a way to inject color and rejuvenate the tailored suit and sportsjacket of the past two years. Now it seems sweaters, slacks, swimsuits and even underwear are targets of the stripe pattern.

Designers are counting on winning stripes as a way to build business on last year's single most popular menswear fashion, the polo-shaped shirt. And the stripe colors are not the familiar preppy variety but an unusual and attractive mix of pastels that have been growing in popularity with men, as well as white ground stripes to go with all the white pants around for summer.

Also different, according to Chip Tolbert, fashion director of the Men's Fashion Association, is that many of those shirts have shed their signature appliques this year "though a couple have managed to sneak them onto the sleeve to be less noticeable," he added.

Even Calvin Klein, who has been partial to solids in his menswear, has used a lot of stripes in his new collection--though, admittedly, not nearly in the profusion that he does with women's clothes. His personal favorites, T-shirts and tank tops, have bold stripes and he has given the effect of stripes in his textured sweaters as well as broad stripes in flat knits that might be worn under jackets.

At Pinky and Dianne for Private Label, Pinky Wolman has pin striped a suede jacket for the most luxurious casual jacket around and stripes linen in tone on tone colors as a way to add texture. She thinks a nifty look on a warm evening includes a white, bib-front, linen shirt with striped sides and white linen drawstring pants.

Pictured: Top left, the white-collared, crew neck pullover in striped cotton knit by Gene Pressman and Lance Karesh for Basco All-American Sportswear is worn under a navy cotton shawl collared jacket.

This pin-striped, suede jacket, center, uses aqua and red for subtle striping on white suede is by Pinky Wolman and Dianne Beaudry for Private Label.

The white bib front and pastel striped shirt by Private Label, top right, an alternative way of dressing for evening, is worn with white linen and cotton drawstring pants.

Calvin Klein's rose toned, boatneck sweater in cotton, bottom left, gets its striped pattern through the textured knit.

The khaki and gray bold striped cotton and linen sweater, bottom right, with three buttons on the shoulder is worn with a gray sportscoat and linen pants.