Visual Arts: Boyle Arts Festival's main visual-arts exhibition has a distinctive character that has developed over the years. It is an idiosyncratic group show that defies easy categorisation., writes Aidan Dunne.

In the past there have been attempts to shape it to a theme or a structure. For successive years, for example, the painters Seán McSweeney and Basil Blackshaw accepted invitations to make their own selection of exhibitors - an interesting idea that produced good shows. But in the long run the annual exhibition seems to have shrugged off attempts to corral it and, like a caged animal making a break for freedom, headed for wide open spaces.

Attending the show is a bit like visiting the Royal Hibernian Academy's annual exhibition. You know it's going to be something of a miscellany, that the emphasis will be on representational art in traditional media, that it's going to be overcrowded, that you won't like everything on offer. But these apparent drawbacks can also be virtues. You can see a lot of work in a short time. You don't have to linger over what you don't like and there are going to be surprises along the way, because new people are invited to exhibit every year.

So while the practice of inviting a huge number of artists - about 80 this year - might sound arbitrary, it is also curiously open in effect, creating a forum in which Louis le Brocquy can, figuratively speaking, rub shoulders with relative newcomers. And the show is extremely popular with its audience, a fact reflected in both visitor numbers and the high percentage of sales.

In numerical terms it may seem far fetched to compare Boyle to the RHA's annual show, but this year more than 200 pieces are on view, and the organisers have gone to the trouble of including a substantial number of sculptors.

Bronzes and stone carvings are troublesome: they present logistical problems and can appear to be expensive. Actually, they are not in real terms unduly expensive. Most of the processes involved in making sculpture are expensive in terms of time, labour and materials, and this is inevitably reflected in the purchase price. But precisely because of the expense of the process, sculptors have been known to forgo a reasonable fee for themselves in the asking price for an individual piece.

Of several straightforward full-figure sculptures included, the best are Mark Rode's Jacinta Standing, a very good realist work, and Gerry Waldron's portly Jeff (Firbolg), which recalls the contemporary classicism of Waldemar Otto, the subject of a major show as part of Galway Arts Festival some years back. There is real sculptural feeling in Melanie le Brocquy's two small pieces, particular Mother And Daughter.

Tom Fitzgerald brings a different aesthetic sense, related to functional craft skills, to his expertly made, highly allusive works. Carolyn Mulholland's fine allegorical panels are evidently two of a series. Anne Cooney's bronzes of organic forms, inspired by seed pods and processes of growth, are sensitively felt and made.

Also sensitively felt are several very good paintings by Veronica Bolay, particularly Snow-Field (Mayo), in which diminutive clusters of coloured forms skirt the edges of a snow-covered field. But this cental expanse of nothing, essentially an empty space, is delicately worked so that it becomes infused with potential, full of possibility, and the whole composition is like an allegory of painting: the process of making and covering a surface behind which there is always a sustaining, underlying reality.

It's not so much a question of making a representation of something as making an imaginative space nurtured by the artist's engagement with the real, by her own concentrated experience of things. All this is beautifully expressed in Bolay's painting.

A comparable preoccupation with a landscape-based subject matter that, in this positive sense, hovers on the edge of not being there at all can be found in some fine work by several other artists. They include Gwen O'Dowd, who shows three Spaces, Seán McSweeney, who like Bolay addresses a central motif that is in a sense mostly empty space, in the form of pools of water in bog cuttings, Mary Mackey, whose terrific series of stained-glass panels, From One Shore And The Other, does likewise, Keith Wilson, who zeroes in on overlooked tracts of ground, Simon English's anonymous, in-between spaces, and Fiona Flinn, whose watery landscapes are all but obscured by screens of misty rain.

In recent years there has been a resurgence in representational painting among younger Irish artists, and various representational strategies can be seen applied in work at Boyle. There is Blaise Smith's muted realism, distinguished by an attentive regard to the actualities of the rural environment, as opposed to the nostalgic denial of the contemporary that is evident in a lot of Irish landscape painting. Geraldine O'Neill's playful trompe l'oeil still lifes delight in presenting us with several layers of meaning. Comhghall Casey is forensically exact in his accounts of an isolated motif. Michael Canning considers the way languages of visual representation structure our view of the world.

Gerard Casey is also analytically inclined in his meticulously calculated images, with their subtle, painterly surfaces. He looks for patterns in nature, and this inclination towards abstraction is comparable to Joe Dunne's methodically structural way of looking at landscape. His paintings, with their angular rhythms, benefit from his feeling for light and atmospheric colour. There is always a great deal of calculated structure in Barbara Warren's paintings, although they are stringently representational. A Memory Of Maumine, with its intimation of reconstructing a past scene in Galway, is a very good, complex picture.

There's a great deal more worth seeing, and, just a few doors down the street from King House, Malachy Costello exhibits some outstanding landscape-based works. One of the great things about Boyle is that commissions on work sold go towards acquiring works for the civic collection, which grows by the year and is now quite formidable.