Moving around in Murphy-Sheehy's fabric shop is a nightmare for all but the wafer-thin. Bales of organza, calico, plush velvet and serviceable tweed take up every square inch, except for a narrow space by the counter.

Behind this, Geraldine Adam, her daughter Jane and son Fionn measure, shear and exchange banter with regular customers.

Geraldine's father Harry Murphy and his partner Mago Sheehy opened their first shop in South Frederick Street in 1946. Fifty-five years on, Geraldine is preparing to hand over the business reins to the next generation.

She went to work in the shop 29 years ago when her father's partner Mago Sheehy died. "I never thought I'd be here still," she laughs.

"I was married with one child and my dad was so thrilled. He was able to sit in Sheehan's pub and watch the horses while I looked after the customers.

"My mother minded the children for everybody and had nothing to do with the shop - she never put her nose in the door."

Harry Murphy and Mago Sheehy were drapery buyers with Pims and Arnotts in the mid-1940s. When they leased their first premises in South Frederick Street, a wholesale drapery was the obvious business to go into.

The shop now trades on Castle Market Street, behind the Powerscourt Townhouse Centre, in a former button and haberdashery store owned by two ladies called Leadbetter. They have hardly any haberdashery now because there's no room, says Geraldine.

"The fabric only came in in the last 25 years. When we moved to the Castle Market Street shop in the 1950s, we were supplying sheets and nurses uniforms to hospitals. Dad made all the bedding bales for Cavendishes hire purchase shop.

"In those days, people put money aside every week for wedding parcels of Foxford blankets, candlewick bedspreads, sheets and towels. The Foxford blankets were sold by weight - we used to weight them on big scales hanging from the ceiling.

"Dad was so easy to work for. He would often close the shop and put a sign up 'gone to Punchestown'. "

Surprisingly, a large part of business these days is with artists, who buy sacking and calico for canvases from Murphy, Sheehy. Drama groups source material for backdrops and wardrobe mistresses browse through the bales for costume ideas.

Contracts with schools around the country for fabric for Home Economics classes are another regular source of income.

Castle Market has become trendy in recent years. Next door to the shop, a smart French patisserie called "La Maison des Gourmands" does a brisk trade. Buskers have arrived on the street - a sure sign that things are looking up in this part of town. Surrounded by the rag trade and with Jenny Vander's second-hand shop across the road, the location couldn't be better, says Geraldine.

"Dad moved here because the rent suited him. A while ago, people didn't know where this street was. It was full of tailors then and South William Street was all wholesale. Des Byrne's grocery shop across the road used to supply sandwiches on tick and there was often a cat on the counter."

Most of the buying now is done by Geraldine's grown-up children Jane and Fionn, who travel to Belfast and Dungannon every month to buy bales of linen. Buying a whole shelf of fabric at a time keeps their prices keen.

One roll of sackcloth they thought they would have difficulty selling ended up as curtains. Lined with red, the sacking became a dramatic fashion statement on an inventive customer's windows, says Geraldine.

The personal nature of business, with families shopping here for generations, makes for a very genial atmosphere in the Murphy Sheehy shop, she adds. "Customers don't mind rooting and making a mess in here. People come back with photographs of debs dresses showing us how nice they turned out. Interior designers buy a lot of Irish tweed for upholstery - something you wouldn't have thought of.

Youngsters come in for bits and pieces to make bags and patches for their jeans."

Pivotal to Murphy Sheehy's success over the years has been the presence of Claire Doyle, who has served behind the counter for 27 years and Marjorie Campion, who has just retired after 18 years in the shop.

Geraldine Adam has recently taken up golf and works just three days a week in the shop, leaving the day-to-day running of the business to Fionn and Jane. The family have a long lease on the Castle Market shop and have tried to buy the premises several times without success.

Rents are killing smaller shops, says Geraldine, who hopes their business will survive, despite the rent going "sky high" at the last review three years ago.

She believes the economic downturn will not affect businesses like theirs. "I don't think we'll suffer. In fact, we'll probably do better in a recession," adds Geraldine, rushing back behind the counter to deal with the queue.