Whose Hat Was That?

Rest assured--the exuberant sense of color and love of pattern that characterize Brian Wildsmith's art in such large-format books as The Princess and the Moon translate superbly in these four board-book-size titles for the youngest audiences. The gorgeously dappled backgrounds and intricate designs (for example, snail shells that look like Ukrainian Easter eggs; a sun and a wrought-iron fence both rendered as rectolinear fantasies) will command attenton; simple but imaginative story lines guarantee reader participation. Look Closer , for example, presents a series of pastoral scenes: ``I passed wild roses and saw something move. What could it be?'' reads one caption. Turn the page, and a detail from the first illustration is enlarged to show three caterpillars curled atop rose leaves. Wake Up invites readers to speculate which farmyard animal is next on the list for reveille; soberly captioned and rigidly geometrical pictures are juxtaposed with fanciful scenes in which the repeated title serves as caption in What Did I Find? ; and Whose Hat conducts a geographical guessing game. A jolly introduction to the pleasures of books. Ages 2-6. (Mar.)