Vintage advertising art from Ireland and Britain will be auctioned in London next month in a sale of some 200 lots, expected to realise more than £200,000 sterling (#325,000).

The Irish and British travel posters auction of railways and London underground art at Christie's on September 12th includes seven Irish posters by Paul Henry. Irish posters in the auction include a very nice image of Blarney Castle (estimate: £900-£1,000); two posters with different views of Sheephaven, Co Donegal (both estimated at £700-£900) and Lough Derg (£500-£700).

Condition and rarity largely determine values. A golfing theme can also increase the value of a poster. The Blarney Castle poster hadn't been seen by Christie's before and it's quite rare, hence its higher estimate. Ms Nicolette White, poster specialist at Christie's, London, told The Irish Times: "Generally, we value the Paul Henrys at £700£900. The Lough Derg one is a little bit less attractive than the other ones so that's a bit lower."

Another Paul Henry poster reads: "To Ireland with ease by rail and sea." Estimated at £500£700, it shows the Dingle peninsula. Its lower estimate is because its condition isn't as good as the others.

A highlight of the auction is "Giants Refreshed" by Terence Cuneo, commissioned by British Railways. Portraying two huge steam engines at rest, it is estimated at £1,500-£2,000.

Posters in the auction were not necessarily used on billboards. "What happened was they overprinted them at the time and then sold them so people could buy them. A lot of them are actually bought by the public. Also, the artist - or anybody to do with the artist - might have had some. Printers had some that were left over. Some people to do with railways have them because they had one left over and they kept it," according to Ms White.

A lot of money was spent commissioning and producing early posters, as it was one of the few available advertising media in the 1930s. "At the time it was the main way of getting information across to people before you could advertise on television or necessarily on the radio."

The main periods of interest are posters from the 1930s, although some from as late as the 1950s - including an Irish aviation poster mentioned below - can be valuable. The posters were designed to go up on billboards. There were two standards sizes: the smaller was 40 by 25 inches, while the other standard size was 40 by 50 inches.

For instance, one of the Paul Henry posters, "Come to Ulster for a better holiday", in the auction is 40 by 50 inches, but most of the posters are the smaller size.

British railway companies commissioned most of the Irish posters. For instance, London Midland and Scottish Railway commissioned the Paul Henry posters of Ireland. They were displayed for the most part on British railways.

However, Irish railway companies also commissioned posters. For instance, an Irish poster in the auction entitled "Killarney - heaven's reflex" by Walter Till was commissioned by the Great Southern Railways. Estimated at £600-£800, it is in very good condition.

An airline poster of Irish interest designed by Edward McKnight Kauffer advertises American Airlines to Ireland. Dated 1948, it is estimated at £500-£700.

Another aviation poster, entitled "Dublin: fly Irish Air Lines", dating from as late as the mid-1950s, is estimated to fetch between £500 and £700 at the auction. Buyers pay the "hammer price" plus a 17.5 per cent buyer's premium. The original owner gets the hammer price minus the auction house's commission.

Christie's charges 9 per cent commission to private sellers and 5 per cent to the trade.

Web: www.christie's.com jmarms@irish-times.ie