How big is the sky? That's the kind of unfathomable question one only expects of small children, but Helen Miranda Wilson's recent "Sky" paintings are sophisticated incitements to innocent questions. If they provide an answer, it's that you can never really know the size of the sky because you only ever see it in fragments. So while the paintings are consistently small in scale (their dimensions vary only between the limits of 6 and 14 Y, inches), they never miniaturize their subject, as small paintings so often do, because they remind you that the "natural" scale for the depiction of a cloud is moot. (Recall the materialist in Blake's "Vision of the Last Judgment," for whom the sun can be described as a fire about the size of a guinea coin.)

In any case, the paintings never feel as small as they really are. Their gravity is high, like collapsed stars that still have the same mass as when they were gassy giants. Their scale, moreover, allows them to present themselves very much as objects you don't lose perspective in the view, in any romantic sense of the unbounded. Instead, each one appears as a slab of celestial substance that's been excised from the larger continuum. The surfaces of these paintings are smooth and ultra-refined, but also dry and, since they don't efface the traces of the painter's hand, fresh: they do not create the feeling, which nineteenth-century academic painting and its contemporary imitators share with photography, that the surface is a sort of film or emulsion within which the image has been laminated

A meteorologist once sent me a manuscript, 150 pages long, establishing the chronology of Van Gogh's landscape paintings by matching their skies to the contemporary daily weather reports. I'm no meteorologist, so I wouldn't know if Wilson's skies are pure observation, pure invention, or a little of both—some titles are as denotative as Boxing Day, 1996, or Midsummer Eve, 1997, but others as metaphorical as Music, 1996, or The Story Teller, 1997. But I'm enough of an art critic to know that horizonless skies are the closest thing nature provides to an allover field, so I'd just as soon see the paintings as abstraction and avoid any truck with meteorological reality whatsoever. Old-school formalist abstraction emphasized its own object quality too, but in order to banish illusion, to vacate the space of depiction. Wilson's paintings use objecthood to intensify illusionism—to give the unshakable sensation of presenting not just a window onto the sky, but a framed section of it. It's a strange twist on art's polarity of materialism and illusionism.

Boundaries and outlines, except for the one between the painting-object itself and its surroundings, count for little in Wilson's painting. Instead, the way a wisp of cloud dissolves into clear blue without your seeing where one ends and the other begins is of the utmost importance. Such transitions are at the heart of the work, and they are realized by a handling of color that is nothing short of wondrous. You wouldn't think the eye could distinguish so many blues, or that (for instance, in depicting the sky's changes at dusk) they could modulate so ravishingly into the most distant reaches of the spectrum. When the distinctions get to the point where they ought to be too close to make out, as in the mottled darkness at the bottom of the nocturnal Hidden Moon, 1996, there is all the more pleasure in discovering that you can still see them.