For all their artistry, calligraphers and letter cutters cannot be relied upon to produce a good read. An obsession with the creation of perfect As and Bs is not the same thing at all as the production of a page of readable text.

Try reading a book set in Perpetua, one of Eric Gill's beautiful typefaces, and you may well find your eye hooked on the ascender or descender of one particular character; then the thoughts of the author will be disregarded as you savour the idiosyncratic ups and downs of a Perpetua P.

A typeface designed by one of the greatest of all letter cutters, Perpetua hovers awkwardly between the mechanistic and the calligraphic; it refuses to flow like Baskerville, Times New Roman or Caslon. And a highly considered calligraphic A from Gill's Four Gospels (for the Golden Cockerell Press) draws the reader, like quicksand, into the arcane aesthetics of the alphabet. Such an A is there to be looked at, a miniature work of art.

Certainly, there are few arts as satisfying as that of the letter cutter; form and function are one, and the meaning of a character is unambiguous. Letter cutters know what has to be done in the making of a J or K, and are free from the creative angst of the avant-garde artist with nothing to say (which is perhaps why, though poor, they are a nice and apparently perfectly happy bunch of people).

A well-cut letter occupies a special territory between art and craft. It is not normally the stuff of London's ever-so and icy cold art galleries. But this week 'Letters of the Alphabet' opened at The Gallery in Cork Street, the scariest art strip of them all.

Commissioned by the gallery, it is an exhibition of complete alphabets and individual letters (plus pounds and dollars signs, an & by John Skelton and the figures 1 to 9).

This is a nice conceit - a way of encompassing the work of a large and diverse bunch of the best contemporary British and Irish calligraphers and letter cutters (35 in all). What is more, because lettering is not considered 'fine art', the works on show are affordable (from pounds 225), and should be considered good value, given the artistry and sheer skill that created them.

To begin at the beginning, Tom Perkins has cut a glorious A in a polished square of Welsh slate. He slices into the rock as smoothly and gracefully as if he were dipping an italic nib into ink and sweeping it across a sheet of perfect vellum. Here is an A unlike any other: it swoops confidently up, down and around, a calligraphic roller-coaster ride reaching out to the edges of the slate. It is beautiful and a hard act to follow. Yet the rest of the Cork Street alphabet, though very much a matter of taste, provides equally bravura flourishes. Sarah More offers what can be described as a deconstructionist D - a cleverly broken letter-form, also cut into Welsh slate (a popular material because it is very dense and rarely splinters, allowing the cutters to carve confidently in finely chiselled lines).

David Baker's N (is for Neon) comprises a gilded Roman capital N cut into slate, superimposed by a neat lower case n in the guise of a blue neon tube. Perhaps there is something a little incongruous about the unlovely electric wizardy hidden behind the slate, but it remains a bright idea.

James Salisbury's S, again cut into Welsh slate and painted and gilded, can be found among a flight of poetic S words, which reads (in flowing capitals): 'Summer's Swallows Skimming Over Sunbeams and Shadows'.

Among the more playful letters are Nicholas Sloan's painted steel and brass F, shaped like a builder's crane (part of a envisaged Meccano alphabet), and Eric Marland's 'P in a Pod' (a gilded pebble set in waxed stone aggregate, a Cambridgeshire clunch).

Several complete alphabets include student work from David Kindersley's studio (these are very Gill-like), and one set into a blue glass plate made by Lida Lopes Cardozo (with help from Pippa Westoby) from the same studio.

If many of the letters appear to have echoes of their neighbours, this should not be surprising. Most of Britain's best letterers and calligraphers were trained directly by Eric Gill and David Jones - Ralph Beyer, David Kindersley and John Skelton (all on show in Cork Street) - who in turn trained such people as Tom Perkins and Kevin Cribb.

This is not because some mafia has a stranglehold on the art of lettering, but because the skill has been taught by a necessarily old- fashioned apprenticeship and studio system. Carving a letter is much more difficult than ladling oil on to canvas: a clever or well-connected painter can get away with a second- rate piece of abstract work, but no letter cutter can camouflage a badly formed A or B.

Gill and Jones remain giants in their neatly hedged field: their closely related yet very different approaches to lettering inform most of the work on display in Cork Street. Where the cocky Gill was formal and robust in his approach to letter forms, Jones - the mystical poet, engraver and painter - was more fluid and romantic.

For Gill, the Holy Grail was the inscriptions carved around the base of Trajan's column in Rome (ancient Roman lettering at its finest); for Jones, Roman austerity was best softened by the lyrical letter forms of Gaelic scripts.

You can see both influences - very much alive - in 'Letters of the Alphabet', which really is a show worth braving the loftiness of London's gallery world for. And even if you cannot afford pounds 200 or pounds 300 for a letter cut into stone or slate, The Gallery has rubbings of alphabets for sale at pounds 50, as well as posters, books and postcards for much less.

You can always try drawing and painting letters by yourself, but if you want to cut, look very closely at Tom Perkins's A and try to imagine the keenness of eye and sureness of hand required - these and several years' training - to make such a lovely and satisfying thing.

'Letters of the Alphabet, a contemporary interpretation', until 12 February, 10am-6pm Monday to Friday, 10am- 1pm Saturday, The Gallery in Cork Street, 28 Cork Street, London W1, 071-437 2812.

(Photograph omitted)