Bored with mainstream and mass-produced eyewear, we embarked on a journey in 2012 to make the best quality, most interesting and meaningful glasses frames.
Right here in Glasgow.
After years of honing our craft, we wanted to share with you how glasses frames are made.
Starting from acetate sheet, here’s a list of the processes we use to make our spectacle frames.
How are glasses made step by step?
#1 Acetate delivery
So, how are glasses made?
At Banton Frameworks, we believe the best place to start is with the best materials. That's why we source the best acetate from Europe’s best supplier.
This bio-material is made from wood and cotton pulp, dyed to any colour, pattern or transparency.
The large acetate sheets can barely fit through our workshop doors, so we cut them into smaller, more manageable strips using a table saw seen in the next step.
#2 Acetate sheet cutting
Using a table saw, we cut the sheet acetate into narrower strips. This can take several hours, depending on the size of the delivery and the shape of the sheets.
Our Italian supplier has various thicknesses and sizes of sheet, which can make cutting them something of a logistical puzzle.
Once they're cut-down, the strips of acetate fit perfectly inside our computer controlled milling machine ready for thicknessing.
#3 Facing
At this stage, the acetate is still raw. This means the thickness can vary hugely within the sheet varying from 7mm to 10mm in the same sheet!
To make it even, we use a milling machine to 'face' the acetate down, removing a fine top-layer off the top. This is repeated on both sides so it's all 8mm thick.
#4 Machining
Using pre-designed digital 'shapes' the acetate is then machined into frame fronts and temples. Various cutting tools are used to sculpt the acetate, adding curves, edges, nosepads, lens grooves, hinge graves and rivet holes.
Don't be fooled. Machining requires great skill and certainly isn't a hands-off process. Each stage requires accurate holding, fixing, speeds and RPM's to ensure a high quality cut.
Rough edges and tool marks are kept to a minimum which is no easy task.
#5 De-flashing
Traditionally, acetate frames were always constructed with rivets.
But today, modern techniques allow hinges to be secured by melting them into the acetate.
This technique is called “hidden hinges” which are predominantly used for mass produced frames.
It simply takes less time, less components and less space in the frame.
Trouble is, just like rivet-hinges, they can come loose over time.
Further still, they can’t be fixed back into place.
You know how this story ends…
That’s why we fasten our hinges traditionally.
We use rivets.
Good old-fashioned solid-steel pins that hold your hinges into place.
If they do come loose, which they sometimes do, they can be re-fixed to make them solid and secure again, because our frames are worth fixing.
A rare thing in today’s throw-away culture.
#7 Bridge bumping
Who doesn't love comfy glasses?
To accommodate your nose, the frame front is heated in an oven to make it soft and malleable. At the correct temperature, it's then swiftly removed and placed under a pneumatic press.
Shaped just like your nose, a little brass 'wedge' is then pressed down into the bridge of the frame front, creating a small bump for your nose to go whilst adding curvature to the frame.
This curvature helps your lenses go-in at the final stages of production.
#6 Tumbling
After machining, the acetate has sharp edges and rough tool marks. To remove these marks and to make them smooth and comfortable to wear, the frame fronts and temple arms are placed inside our tumble polishing machine.
Inside one of four wooden chambers, the fronts and temples are mixed with tumbling 'media'. The media ranges from coarse to super-fine wooden particles to which polishing paste is added.
Sealed with a lid, the machine then rotates the chambers to churn the media and components within.
Through continual abrasion, the media particles rub against the frames making them smoother and smoother as they cascade within the chambers.
Each of the 4 grades of media accumulates to 72 hours of continual tumbling which removes all the tool marks and leaves them smooth and shiny.
Further hand polishing is required, but at this stage, the acetate components look nearly perfect.
Tumble polishing is truly an amazing process. It's addictive, tactile and incredibly satisfying to see the acetate come to life.
As if I haven't written enough about tumbling, you can see the four chambers of our tumble polishing machine in the image above.
Lucy and I meticulously inspect the frames and temples between each stage of tumbling to ensure we're both happy with the surface finish.
As with any maker, you have to be in-tune with your machinery and tools to know if the components need further tumbling or not.
#7 Laser engraving
After a quick hand polish, the interior surface of the temple arms are then placed into a jig on our laser engraving table.
Using a high-speed laser beam, we engrave various details such as the frame model, dimensions, CE and UKCA markings.
And because just two people make your glasses, we add our signatures on-there too.
Artists always sign their work.
#8 Assembly
This stage always feels like a huge leap forwards, because the two temple arms can finally be attached to the frame front.
Using nylon coated screws, the reassuringly solid metal hinges are screwed together by hand.
As a nerdy insight, we take immense pleasure from the smooth articulation of our Swiss-made hinges.
Opening and closing the temples is a truly tactile experience - one you can savour when you unpack your new frame.
The nylon coated screws ensure they don't come loose, even after thousands of swivels.
#9 Temple heating
At this stage, you may have noticed the temple arms are still straight.
To make them curved and hooked, we insert them into an oven which heats just the temple ends.
Like a carousel, this oven rotates around so we can add one cold frame as we take another hot one out.
#10 Temple dropping
Once heated, the softened temples are then curved using this pneumatic bending machine. Using accurate moulds, an arm swings downwards to 'drop' the temple ends.
The temple 'drops' are what hook behind your ears which helps keep your frame in-place when you're wearing them.
if you need a tighter or looser fit, we can adjust your temples to suit as part of our unlimited adjustments service.
#11 Hand polishing
During heating and curving, the fully assembled frame becomes blemished and therefore requires further hand polishing.
Using four increasingly fine grades of polishing compound, the entire frame is skilfully brought to a high-gloss shine.
The acetates goes from a dull shine to a gleaming, impeccable lustre. Slow and time consuming, this process is what really makes the acetate sing.
No shortcuts.
But oh so worth it.
#12 Steam cleaning
From every single stage prior, the frame gathers a lot of polishing debris, dust and wax. With so many fine nooks and cranny's, the most efficient cleaning method is using steam.
Just like a coffee machine, we blast pressurised steam to make the frame perfect clean, ready for drying and lens fitting.
#13 Demo lens cutting
As a semi-natural material, acetate has the habit of warping over time - especially if it's unsupported.
This is the main reason why we cut and fit (non-prescription) demonstration lenses, to keep the frame in the correct shape before you try them on at home.
As the lenses are curved, they maintain the curvature of the frame whilst making the glasses look nice and finished.
#14 Demo lens fitting
To fit the demo-lenses, we gently heat the frame front so the acetate expands and becomes more malleable. This makes it easier for the lenses to pop-in without damaging the pristine acetate rim.
#15 Packing
Just six times per year, we release our batches of limited edition, handmade eyewear. Tied with a branded ribbon, we envelope your glasses in a protective hard case, sealed inside a luxurious packaging carton.
Hopefully you've enjoyed seeing some of the key-processes that go into making a pair of glasses.
FAQ's
Where are glasses manufactured?
To an extent, most, if not all high-quality glasses frame are handmade
The detail is where they’re handmade.
Today, the majority of eyewear is predominantly mass-produced in Italy, France, Japan and China using a combination of manual skill, semi-automatic and automatic production processes.
As of 2010, direct-to-consumer brands have begun to grow, selling acetate frames at very low price-points. The processes used to make these glasses frames are affordably labour intensive from the lower costs of overseas manual work.
How long do glasses take to be made?
The time to make a pair of glasses varies on the volume of production.
Bespoke glasses are easily the most labour-intensive to make, taking it through each of the necessary processes. Often, these are done at a craft-based volume which usually consists of labour-intensive processes such as hand-cutting, hand-sanding, tumble polishing, hand-riveting and hand-assembling.
Small batch glasses (like ours) typically take around 6 weeks to make, taking them through all of the processes listed earlier in this article. Unlike a bespoke one-off frame, batch production helps streamline each stage of the production process, but without high volumes. This makes the frames less abundant unlike mass produced, mainstream eyewear brands.
Mass produced glasses are much quicker and involves batch production. Numerous glasses frames and temples (arms) are processed at once using semi-automated or even fully automated production processes.
The spectacles and components are taken through these stages more quickly and more consistently with less human intervention.
How were glasses made?
The earliest glasses frames were thought to have been made at the turn of the 12th century from naturally abundant materials such as bone, ivory, leather and wood.
Back then, these natural materials would have been hand-carved to accept the very basic and round lenses of that era. These glasses were usually made of two separate lens-holder, similar to two magnifying glasses joined together.
In more recent iterations, spectacles and sunglasses began to benefit from material developments such as polymers. In the mid-1900’s bio-plastics such as cellulose acetate were becoming more popular resulting from the post-war scarcity of natural materials.
The college of optometrists has put together an informative article about the history of the earliest spectacle frames which you can read here.
What is the best material for eyeglass lenses?
Today, the preferred material for spectacle-lenses is high-density plastic.
Although glass provides the best optical quality, it has been predominantly outdated by several different types of plastic used to make glasses lenses.
These include composite, standard plastic, mid-index plastic, high-index plastic, polycarbonate and high-definition plastic.
You can read about these in more detail via the article by The Vision Council.
How are prescription sunglasses made?
The eyeglass lens manufacturing process for prescription sunglasses is carried out using the same lenses for spectacle frames but with a UV protective coating known as a “tint.”
Prior to cutting and edging the lens, the UV/protective coating is applied by dipping it into a bath containing the liquid tint. Different colours of tint can be applied to the lens which generally consists of brown, green, blue or grey.
Gradient tints can be achieved by from inverse dip-times in the bath. Upside-down, the top of the lens is immersed for longer than the lower region of the lens to create the tinted gradient.
For consistency, both lenses are dipped together which can be assisted with the aid of a dipping-arm machine.
