When we covered SEH Kelly last year and talked about the writing of its founder, Paul, some readers commented that they'd like to read more by him. So I asked if he'd write a little piece about the world of London's garment factories. I hope you enjoy it.

"Consider the bumblebee. A ludicrous little fella: oblivious entirely to the impossibility of his fuzzy and rotund form being able to fly. One might wonder, if he stopped to think for a second, might he drop from the sky and be forced to do something more probable with his day?

We're long past speculating how he does what he does, of course, but the same cannot yet be said of the garment-manufacturing industry in London, which is a thing spectacularly indifferent to its own reality-defying state of being. It is the outcome of a confluence of economic, cultural, and historical factors, and really, today, shouldn't by any stretch of the imagination exist.

It is out of time and yet of no time at all: buoyed just above drowning by the lap of new customers — from graduates to entrepreneurs to dilettantes — and the swell of new workforces from abroad.

It is run with instinctive plate-spinning management, which ensures enough money comes in each week to fill every envelope with wages, as well as the sundry other overheads of doing business in the capital.

This is a trade into which the men and women at the top were born. They ran as children around the factory of their mother or father, who were most likely immigrants from one of a half-dozen countries, and whose know-how from back home slotted profitably into what was then an industry at an apex of prosperity.

They are run now the same as then: as sustainable family businesses. The men and women on the machines, in the cutting room, in the finishing or packing section — they're not all family, per se, but a sizeable chunk of them have a shared personal and professional history in the capital that goes back decades.

The average age of the workforce is mid-40s. The youngest are recently in London from mainland Europe. The middle-aged from further afield, whose parents arrived here fifty years ago. The oldest came from the same and other parts at the same time, but already at working age.

They all get along, all respect one another's cultures and faiths, all queue for the same microwave at lunchtime. It is wonderful.

The typical clothing factory in London also houses people who long ago left the career-ladder, or were never on it in the first place.

As you work your way along from the august pattern-cutter to the woebegone cabbage-buyer to the enthusiastic travelling trimmings merchant, there is a high incidence of what you might call "characters". It is a self-knowingly motley crew of fantastically talented people, whose skills, whether innate or learned, would be and oftentimes have been wasted in other lines of work.

"What’s my peculiarity?" the pattern-cutter asks me, out of the blue, one morning. To which the only answer is, "Where do I start?"

Our house style is on the surface an outcome of the design process, then pattern-cutting, and then a choice of materials. But it is also the result of a factory's "handwriting", which is understandably never remarked upon by consumers: only really being something of concern from the inside looking out.

Yet this handwriting, which manifests as a few seemingly prosaic choices made during cutting and making, informs significantly how a garment looks and feels — and increasingly so with time, as the garment is worn and washed again and again.

Take how a cutter cuts a patch pocket: which parts he fuses and with what, and how he marks it and tells the next person in line how to make it. Sounds simple enough, right?

But numerous fluid decisions, governed unless advised otherwise by his personal preferences, will make a strong double-layer pocket, or a finer pocket but with a line of stitching across the top. Then pile onto that the weight and shade of thread, and the stitching style, and the presence of not of bar-tacks, and you can see how something as simple as a rectangle of cloth can be made in a dozen different ways.

For me, there is a sense often that if you’re not driving them all up the wall, then you’re not doing it right. If you design something that is difficult to make — for the right reasons, of course — then it is a point of self-satisfaction, because your work has something new to say.

There's our new field jacket, for instance (above), whose sleeve looks like a side-body and side-body like a boomerang-like weapon from a hostile planet from Star Trek. It has a back-to-front Magyar sleeve, which is odd, and is complicated further by a "patrol pleat" on the back. You have to have faith in the cutter to figure that one out.

Another example is the stacking of layers of the through-pocket of our balmacaan (below). Through-pockets usually start with a welt pocket on the outside running to a patch on the inside.

Ours has an in-seam pocket covered by a pocket flap on the outside, running through to a welt pocket built into the side-facing on the inside. Even typing it is confusing: imagine what it is like for the poor machinist.

Sometimes pushing the reasonable goes too far. There was the great leaking indigo catastrophe of 2012, or the hand-woven linen tweed that even fusible couldn't tame, or the experiments with triple-layer Kevlar or the linen intended for binding books. But heck — you never know 'til you try, do you?

Factory work is by definition fragmented. This makes it a distant cousin to smaller-scale tailoring or dressmaking, say. There are few in the manufacturing industry who can make a jacket from start to finish — at least at the speed required to base a business on it — because otherwise they wouldn't be working in it.

There are the top sample-machinists, of course, with the wherewithal to assemble just about anything from a tightly wrapped bundle of cloth, from a traditional tailored jacket to the most creative "is that the front or the back?" catwalk piece.

But, to a bystander, this is procedural, problem-solving approach to garment-making rather than the romanticised craft-led one seen in other parts of the trade.

Many jobs in the factory, anyway, are things like making a pocket, the same pocket, from a pile of pocket-shaped pieces, ten hours a day, six days a week. Or a collar, or hem-band, or, moving around the factory building, whipping button shanks, or trimming buttonholes, or packing shirts.

There is no marvelling at an exquisite coat hanging in the finishing section which will next week be hanging in Manhattan or Ginza or Hackney. Whether the novelty has worn off or they didn't care in the first place, I don't know.

No time to dwell, anyway. It is desirable for a factory to take on too much work to guarantee the lines are always busy. (Outside the capital, capable machinists are fewer, but since turnover of staff is lower, a factory can better afford training.)

And for the customer, London is more competitive than anywhere else in the known world: you really must bob and weave to get what you want when you want it. It is a supplier's market. If your patterns aren't ready, or cloth, or trimmings, you can find yourself without the room on the line which last week you were promised.

Steadying the ship, thankfully, is the factory boss, who whether beleaguered by deadlines or on top of the world, is always in the eye of the storm.

He or she who knows which levers to pull and when: where to get the wages at the end of a quiet week, whose second-cousin to bring in to hand-sew those taffeta dresses, or which repairman to call when the shirring machine breaks down again.

This is knowledge that isn't written down and which is unlikely to be taken up by the next generation. The careful balancing act that manages and maintains the industry here in London is in safe hands for another couple of decades.

Where it goes beyond that, though, with forward-planning no one's forte, is anybody's guess. But who's to say it simply won't keep on keeping on?

Maybe that's the bumblebee's secret. The beauty with occupying a niche which seems to everybody else much too much like hard work is just that: you're welcome to it."

Photography: Factory, SEH Kelly; Paul and SEH Kelly products, James Holborow