Visual Arts: Reviewed Do I have to?, From Bethany to Beacon Fallsand  Trek Elk.

Do I have to?Gabrielle Quinn.The Paul Kane Gallery, 6 Merrion Sq Until Sep 8 087-6478423

From Bethany to Beacon Falls, Donald Teskey.Rubicon Gallery, 10 St Stephen's Green Until Aug 24 01-6708055

Trek Elk, Robert Janz.Peppercanister Gallery, 3 Herbert St Until Sep 14 01-6611279

Gabrielle Quinn's Do I have to? is an intriguing exhibition of drawings and objects, difficult to categorise in conventional terms.

All of Quinn's work is beautifully and meticulously made but, more than that, it is made obsessively, following her own systems and processes, so what she comes up with is out of the ordinary and not amenable with standard definitions of, say, composition, subject and finish.

To begin with, she has her own, idiosyncratic nomenclature. Once you get to grips with that you might like to note her way with titles: each piece has its own detailed title, and then an entirely different, equally detailed alternative title. The effect is not, as you might think, to undermine the whole notion of titles, but to throw it into relief. Why not have alternative titles, offering another slant, the preoccupations of another day in the artist's life? Quinn's titles never seem parodic, even though they are, on occasion, light-hearted. And they never seem glib or gratuitous. They are dense and often quizzical.

As for her nomenclature, her minutely detailed drawings have something in common with the appearance of scientific and technical illustrations. Many of them look as if they might depict organisms or details of organisms of an unspecified nature and scale. But each drawing also has the appearance of having developed organically to its point of completion, forming as it grew, without reference to any exterior subject, and according to parameters imposed arbitrarily by the artist. She terms the drawings "residues", and they form part of a category she calls "contaminated art". The contamination she refers to is the infiltration of aspects of the everyday, including "the banal", into the formation of the art work.

The larger pieces we see in the exhibition were seeded by tiny drawings called "nerbals", copies of which were sent to a number of individuals with the aim of generating a kind of sympathetic energy. If all of this sounds eccentric or odd, it is, but it's also interesting, and it leads to the creation of a body of fascinating work, including a series of exquisite sculptural pieces in Perspex boxes. These latter works recall Barrie Cooke's Bone Boxes in several respects.

Quinn's titles sometimes offer what might be clues about what we're looking at in the drawings, but they don't really pin anything down. Often they could plausibly be greatly magnified views of insects or microscopic creatures or, equally, sections of much larger creatures altogether, including humans. A recurrent Picture Wig is apparently just that, a form that grows around the rectangular outline of an otherwise invisible picture - a good example, presumably, of contamination.

Quinn's procedures recall the work of Georges Perec (who wrote a novel that excluded the letter e) and the Oulipo writers group. The artist Paul Mosse, who generates fantastically detailed, world-like painting constructions, also comes to mind. What they do may sound self-indulgent or irrelevant, but in fact it is compelling and often revealing. By adhering to various kinds of arbitrary constraints and systems, for example, they point to the constraints within which we operate in the world.

WITH FROM BETHANY TO BEACON FALLS, Donald Teskey departs from the Mayo shoreline that has formed the inspiration for one of his strongest bodies of work to date and looks to the woodland of rural Connecticut. There he enjoyed a residency at the Josef and Anni Albers Foundation, an artists' retreat consisting of a dispersed cluster of buildings spread out among the trees - lots of trees, of various species. He is no stranger to buildings as subjects. Prior to the shoreline landscapes, he explored coastal towns and Dublin city. Trees featured from time to time in the city landscapes, but a forest, and what seems to be a particularly dense forest at that, presents new problems for the painter.

Perhaps the clue as to how he might tackle it lies in the way city street in many paintings became networks of canyons, suggesting lines of approach, paths to follow, directions to take. As Gordon Teskey notes in his catalogue essay, the woods block our way into the picture, filling up the foreground. But Donald Teskey looks for points of entry, providing us with pathways, clearings, pools, buildings, distant splashes of sunlight, setting up the means by which we can negotiate the spaces.

His own working notes, reproduced in the catalogue, reveal that he was struck, and perhaps perplexed, by the verticality of the landscape after the horizontal expanses of the shoreline. A certain air of mystery that attended his city paintings, with their suggestion of hidden destinations just around the corner, of people just having disappeared out of frame, returns in the forest work. The paintings easily solve the problems by the terrain. They keep us busy, engaging the eye with their rich textures and complex spatial patterns.

Robert Janz's Trek Elk at the Peppercanister Gallery is even more vibrant and inventive than his show there last year. He is best known for his fast-paced accounts of flowers blooming and fading, and there has consistently been a performative aspect to his explorations of evanescence. A fine draughtsman with an instinct for expressing energy through form, he has also emerged as a strikingly good sculptor.

While there are many fine paintings in his current show, they are somewhat upstaged by a veritable menagerie of animal (and a couple of shaman) sculptures. In these, again, Janz excels at conveying energy and vitality. He builds figures out of twigs and box-wood fragments, using glue and thread and paint. His emblematic creatures include elk, wolf and shaman, and there is a mythological dimension to them. They are in a way physically insubstantial, but they are real presences, brilliantly observed and demonstrating Janz's gift for expressive line.