British shirtmaking has always been famed for its cutting. The modelling of a three-dimensional shape onto two-dimensional paper panels is an intense intellectual and creative endeavour – one that few will ever master. The visitor to Turnbull & Asser’s bespoke store on Bury Street will meet such masters.

The cutter in Bury Street is both style consultant and craftsman. In the store they walk the customer through the dizzying array of colours and cloths, explaining the virtues of twill and poplin, butcher’s stripe and gingham check. There are over 2,000 shirtings available and so one needs a good guide.

The style of the shirt itself is no less personal. There are 12 stock collars to start from and 11 basic cuffs. But of course the virtue of cutting a collar pattern by hand is that it can be any shape at all. The stock options are more a jumping-off point – a launchpad for the customer’s imagination.

Once the style is decided and the measuring begins, the cutter shifts personality. He is now a craftsman, intent on the precision of the 20 measurements required, as well as copious notes about posture and stance. No man stands bolt upright, and so the cloth must be cut to curve over his back, yet fit smoothly into the shoulder and sleeves without even the hint of a ripple. The amount of excess cloth in the sleeve is also crucial, as it allows the cuff to remain fixed obediently on the wrist.

As he stands, breath held, with tape measure running across his shoulders, the customer can’t help but notice the photograph of Prince Charles on the wall opposite, signed with best wishes to Turnbull & Asser, nor the fond note from Sean Connery, expressing his gratitude for such sterling service. Bury Street is a welcoming space, but also a revered one.

To witness the construction of a Turnbull & Asser shirt we must fly 115 miles to Gloucester, a traditional centre of shirt making in England and the location of the brand’s dedicated factory. There, 86 experienced men and women labour over the making of a perfect English shirt, translating those paper patterns into cotton panels and carefully stitching them together.

There are many different aspects of the process that contribute to Turnbull & Asser's superior quality. The hand cutting, for example, or the construction of the side seams, which involves four layers of fabric folded back on each other within 3/16 of an inch to stop it splitting. The staff swear by their durability.

In fact, the experience of the staff might be the most important factor in Turnbull & Asser’s reputation for excellence. It guarantees consistency and attention to detail. Kathleen Cope and Bette Elton, for instance, are twins who joined the company together in 1964, two weeks after turning 15. They have been loyal staff ever since, and today are supervisor and factory floor manager respectively. The twins aren't alone in enjoying a long career at Turnbull & Asser – many of the company's loyal staff have worked for the company for 20 years or more, refining their skills at making the perfect shirt.

They have dealt with many strange requests over the years, including matching nightwear for boys and their teddies, and slings for both Daniel Craig and Prince Charles when they injured their arms. Nothing phases them, however, they remain ready and waiting for the next Turnbull & Asser customer’s highly particular, highly personal order.