Sackville-West's colorful, articulate letters to Virginia WoolfThe Letters of Vita Sackville-West to Virginia Woolf, edited by Louise DeSalvo and Mitchell A. Leaska. New York: Morrow. Illustrated. 448 pp. $17.95.

Its (sic) queer that diaries now pullulate. No one can settle to a work of art. Comment only.... Shd. one judge people by what they write? Shd. people show their naked skins?

So mused Virginia Woolf in the pages of her own diary during the summer of 1939. To diaries we might add biographies, autobiographies, and collections of letters. One reason few of Woolf's contemporaries could ''settle to a work of art'' may have been the shadow of impending war. The profusion of diaries, letters, memoirs, and biographies published these days, however, seems more related to readers' tastes than writers' predilections. The need for the personal that poetry and fiction can fulfill may also be met by the biographical , which provides the added fillip of appearing to unveil real people in their ''naked skins.''

Virginia Woolf first met Vita Sackville-West in 1922. Vita was 30, a successful, if fundamentally second-rate writer, the wife of diplomat Harold Nicolson, and the veteran of several tempestuous love affairs. Virginia was 40, the author of three novels, noted for her wit and intelligence, but her most famous books were still to be written. Vita was dazzled by the introspective, subtle, acerbic Virginia, while Virginia, beneath her reserve, was captivated by the dashing aristocrat who would serve as the model for her novel ''Orlando.'' Their friendship endured until Virginia's death in 1941.

This collection of Vita's letters displays what was undoubtedly the more engaging side of her vibrant, often turbulent personality. By including some of Virginia's replies (Vita's complete letters are available (Harcourt Brace Jovanovich)), editors Leaska and DeSalvo give us a sense of the relation-VITAVITA

ship between the two women: Virginia, the stronger artist, but the weaker in life; Vita, the bearer of vitality, awed by Virginia's superior intellect. In life, as in drama, we find ourselves playing roles. Leaska's introduction suggests that Vita also played the role of mother to a deliberately dependent Virginia. Letters - even diaries - are not necessarily more ''naked'' than fiction. Self-revelation and self-presentation are inevitably inventive, just as invention and fantasy are self-revelatory. Vita's novels, as she confessed to Virginia, were ''bad.'' Her poetry, which she hoped was better, was not as good as she had hoped. The letters she wrote Virginia, however, are colorful, affectionate, interesting, and definitely first rate.