These little dots have lives of their own

You can't help feeling sympathy for Fiona Banner's father. When the young conceptual artist announced that she had been given her own show in the Tate Gallery's Art Now series, Mr Banner timidly asked his daughter what she intended to include. "So I said, 'It's the Tate, Dad: you know, paintings and sculpture.'" Her father's relief was obvious. "He said, 'Oh: you mean ..." - Banner hoots with laughter - "you mean ... bronze?"

Well, no. Fiona Banner's sculptures - her first, if you exclude a pair of mirrored sunglasses with the lenses turned back to front ("Like kissing yourself," muses their maker), are made of Styrofoam. Banner's sculpture series, created specially for the Tate show, is entitled Full Stops, because that that is exactly what it is: a sequence of full stops, taken from type fonts including Courier, Century and Wing, and blown up enormously in three dimensions. "I discovered one called Fantasy Subterfuge Overlay the other day," says Banner, with the glint of a lepidopterist bagging a new variant of Cabbage White. "It was very exciting."

Consider the pedigree of Full Stops, and you will see how her father might have developed a certain wistfulness towards bronze. Last year, Banner published a book called The Nam: a thousand-page, two kilogramme work which lists, in unbroken narrative, the artist's recollection of various Vietnam films: Apocalypse Now, Platoon, The Deer Hunter. ("They spill out of the helicopters like they can't wait to be on land again. Other choppers come in, they land shakily, on a rut. The sound of gunfire can be heard in between the sound of the blades bat bat batting." And so on, and on, and on.) "I kept wondering what kind of publicity to put on fly-posters,," Banner says thoughtfully. "Then it came to me: 'The Nam: It's Unreadable!' " She chuckles. "It's what a novelist friend had said to me: you can imagine how pleased I was. So I decided to make this thing, sorry, this work, this mighty work, called Trance, in which I read my apparently unreadable book on tape." Banner pauses defiantly. "On 22 tapes, actually. Hah! It's a Joycean thing."

And the full stops? Ah yes. "Producing Nam had been something of an epic, so its end seemed like a culminative moment, a full stop," says Banner. "Maybe that was why I looked around London and suddenly saw that it was full of neon words, but no neon full stops. I went down to a sign shop, and they agreed: there aren't any. So I set about designing one." This Ur-stop, hailed as the world's smallest neon installation, was exhibited in a show at London's Frith Street Gallery last summer.

The Tate Full Stops are actually rather beautiful. Virginia Button, curator of the Art Now series, compares them, not entirely fancifully, with Brancusi. Even more importantly, they mark some kind of ultimate moment in Banner's heroic refusal to take things as read. I use the metaphor advisedly. The Nam may be a jokey thing (its creator describes her magnum opus as less coffee-table book than coffee table); but its punchline is entirely serious. Banner is bothered by the way our rational responses to things are shaped by pictures of them: something of a moral problem for a visual artist, and one which she she explores obsessively, blurring the borders between words and images in her own work.

Banner's own perception of the Vietnam war has, she says, been entirely shaped by film, "even though I can see what's going on - characters in one movie reappearing in the next, Coppola using helicopters in Apocalypse Now and then every Vietnam movie suddenly having helicopters in them." The way one script sliding seamlessly into the next guys the way cinema tends towards self-perpetuation; turning films into scripts rather than the other way around exposes the seduction of visual imagery. By resolving pictures into the thousand words they are supposedly worth, The Nam asks whether they are worth anything at all.

The truth is that Fiona Banner just cannot take things at face value, typefaces included. The first thing you notice about her Full Stops are their bizarre inequalities. Courier, for example, is nearly five feet high, Wing just under two; one is spherical, the other ovoid. This is not glyptic licence, but fact. Although Banner's full stops are hugely magnified, they are all magnified to the same scale. The truth is that those negligible dots have secret lives of own.

"Did you know that Helvetica has square full stops?" asks Banner. The discovery is faintly disturbing, like nature-programme revelations about mites on human skin. Only lovelier. "I chose Styrofoam for the Full Stops because, like them, it is a material that only usually exists as a negative of something else, as packaging around a vacuum cleaner," says Fiona Banner. "Both physically and conceptually, it is so light as to be hardly there at all. It seemed to me the only material in which to sculpt something so poetic that it exists only as a breath or a pause."

As you will have gathered, Banner is fascinated by communication: "how something like Helvetica can become such an amazing conveyor of information." One perverse side-effect of this is that her works are difficult to read: sometimes because they are too long to take in (The Nam), sometimes too large. (The Desert, Banner's huge homage to David Lean's Lawrence of Arabia - "A great moment in the history of wideness," says Banner - could only be viewed from a couple of feet away.)

The work in Art Now takes this perversity to extremes. A canvas, Break Point, describes the car chase in Kathryn Bigelow's 1991 cult film, Point Break. The text is off-puttingly tedious; words crash into each other in a sort of painterly onomatopoeia. They behave not like words, but like brush-strokes. Except, of course, that they are words. Try to read the work like a painting and it keeps turning into a page; read it like a page and it turns into a painting.

Suggest to Fiona Banner that this might be troublesome and she looks faintly appalled. "Really?" she says, eyeing the picture with evident amazement. "It seems completely self-announcing to me." I suspect her father may disagree.

'Art Now 15': Tate Gallery, SW1 (0171 887 8000), 1 Sept to 8 Nov