Architecture: Is the writing on the wall for public inscriptions?: There is more to lettering on buildings than many young architects realise. Peter Dormer looks at some good and bad examples

Every few years an attempt is made to gentrify that lively, if seedy, satellite of Soho known as Leicester Square. Mercifully, no amount of tasteful railings, paving or bijou theatre ticket chalets can civilise the raucous voice of the fairground lettering on the surrounding cinemas, theatres and souvenir shops. The boot- black Odeon has letters the colour of boiled shrimps, while the Empire's light- bulb lettering twinkles in Pearly King sans serif. The souvenir stores and newspaper stands sport signs of vinyl and felt-tipped pen. And perhaps, in London's entertainment land, this is as things should be.

As Edward Johnston, the pioneer of modern British lettering design, said in 1906: 'I do not see how you can make letters which will make people see them, whether they want to or not and no matter where they are, without making them hopelessly loud and intolerable and a public nuisance.'

Today he would have to accept that commerce has our licence to be vulgar. Yet he might have noted that within the public sector at least there has been the occasional substantial lettering achievement, including his own famous work for the original logo and lettering used by London Underground - the Johnston sans serif display face of 1916, commissioned by Frank Pick.

Such thoughtful, purpose-designed lettering is, however, uncommon. The more common practice among architects seeking to use giant lettering on buildings today is to take a book or poster typeface and enlarge it. This tactic is almost guaranteed to backfire, as you can see on the outside back wall of the Sainsbury Wing of the National Gallery in Trafalgar Square, by the American architects Robert Venturi and Denise Scott-Brown.

Cut into the stone facade are the words 'The National Gallery'. The letters are in the architects' own version of Times Roman, a newspaper face designed by the great typographer Stanley Morrison. Venturi's intention might be honourable - it should add dignity and interest to the dull surface of the building - yet the effect is ignoble: the building looks like a mass-produced loaf of bread with the factory name stamped on it. You cannot blow a typeface up to a size it was never intended to be and expect it to look right.

Inside the Sainsbury Wing, however, the stone-cut lettering above the entrance desk in the foyer is a joy. The letter cutter, Michael Harvey, also worked with a roman typeface, of the mid 19th-century - but redesigned it in such a way that it was both suitable for enlargement and for direct carving. He has kept the elegance of the classical letter and his deep, V-shaped incisions make the best of the sunlight and shadows that play on them.

The carved roman letter face continues to be popular among architects and letter carvers because individual letters look distinct, yet blend harmoniously. It is seen in its original and most famous form on the base of the column in the ruins of Trajan's Forum, not far from the Colosseum in Rome. It was erected in AD114 to celebrate the triumphs of the Emperor Trajan and the lettering has provided the inspiration for subsequent generations of classical letter designers.

This letter form keeps being reinvented because it works so well, although as Sarah More, an independent letter carver and designer, points out, Trajan's lettering was designed for northern Italian light; in drab English light, colours (gold is the most popular) are needed to bring out the full quality.

The revival of carved Roman lettering on 20th-century buildings owes much to Eric Gill (1882-1940), whose work in this field was heavily influenced by Johnston. Some fine examples of his carved lettering can be seen on the Leeds University War Memorial and the Stations of the Cross in Westminster Cathedral. The leading contemporary architectural letter carvers of today are Gill's disciples. David Kindersley, a former apprentice of Gill's, has been the most influential post-war letter carver, and his pupils and son, Richard, have in their turn taken up Gill's chisel.

Richard Kindersley's current passion is carving directly into brick rather than stone. 'The direct carving of brick is unlimited in form and shape, free flowing over the surface,' he says.

Of the lettering he carved for the Shakespeare Centre, Stratford-upon- Avon, for example, he says: 'The carved lettering softens a large expanse of brickwork and links it to a lintel below, and the horizontal thrust of the building. The letter form is deliberately wide to enable it to be legible when viewed diagonally from the street.'

Richard Kindersley and other notable carvers such as More, Alec Peever, Tom Perkins and the Incisive Lettering Partnership of Annet Stirling and Brenda Berman (who worked on the National Gallery project) are among 20 or so people listed by the Crafts Council as available for architectural projects.

Most young architects, however, know little or nothing about lettering. As one letterer comments: 'They cannot imagine how letters will look when they are made. You have to keep fiddling with a design to get it accepted because what they expect is something that looks like text on a page of a book. That's not how lettering on buildings should work.'

There is another problem, however, that threatens to slow down the revival of carved architectural lettering: the ownership of buildings. It is one thing for public institutions such as churches, hospitals and museums to commission integrated display lettering that will very likely last the life of the building; but office blocks, warehouses and the like change ownership with increasing frequency, and it is impossible to rub out carved letters.

Old names can be filled in messily with stone, brick or cement, but as Sarah More says: 'It can be nice to see a building's history through its lettering.' It will be intriguing to see how the Shirayama Corporation of Japan, the new owner of County Hall, London, deals with the lovely lettering facing Westminster Bridge, which reads accusingly: 'The Home of London Government from 1922 to 1986'. Will the company erase these letters to sever the link with a controversial past, or leave them as a reminder of a government that turned a civic institution into a five-star hotel?

Lettering in public is an emotive issue - and it always has been, according to to David Pye, one of the elder statesmen of post-war craft and design. He wrote in The Nature and Art of Workmanship (CUP, 1968): 'I have seen in Rome - I think it must have been in the ruins of the house of the Vestals - lettering carved on the bases of the statues. It looked as though it had been done with a blunt tool by a drunken man. And only a little way off stood Trajan's Column with that lettering on it which all the world now knows. What must they have thought when they saw what they had fallen to? It could only have been despair.'

Or perhaps that part of Rome was the Leicester Square of its day.

(Photograph omitted)