Pick up a handmade Japanese frame and you notice something straight away. The weight is different — less of it, distributed more evenly. The surface has a depth to it, not the flat shine of something turned out by a machine. The hinges move cleanly. Even before you put them on, the frame tells you something was done to it that takes time.
That quality doesn't happen by accident. It's the product of a manufacturing process that involves over 200 individual steps, most of them carried out by hand, by craftspeople who have spent decades doing exactly this. Here's what that process actually looks like.
Where Japanese handmade eyewear comes from
Almost all of it comes from one place: Sabae, a small city in Fukui Prefecture on Japan's western coast. Sabae produces around 95% of all eyeglass frames made in Japan — a concentration of expertise that has no real equivalent anywhere in the world.
It started in 1905, when a local farmer named Gozaemon Masunaga; the same family behind the Masunaga eyewear brand stocked here at Sun of Japan; began teaching frame-making to the farming community as a way to earn income during Fukui's long, snowbound winters. The craft spread through the region, passed from family to family and factory to factory, and by the early 20th century Sabae had become Japan's undisputed centre of eyewear production.
What sets Sabae apart today isn't just history. It's the density of specialist knowledge; hundreds of small factories, each mastering one or two stages of the production process, working together in a system of shared craft that makes the finished frames possible.
The making process — step by step
Japanese frames are made from two main materials: acetate and titanium. The path from raw material to finished frame is different for each, but both share the same underlying commitment; that the critical stages are done by a person, not a machine.
The Material
Acetate is derived from natural cotton and wood fibres, compressed into dense blocks or sheets. It can be cut, layered, polished, and shaped in ways that synthetic plastics can't match — which is why it's the material of choice for brands that want colour depth, dimensional complexity, and a surface that improves with age. Brands like Factory900 and Masunaga have built their entire design languages around what acetate can do in skilled hands.
Titanium is a different challenge entirely. Cold-forged from wire at room temperature — no heat applied — it's shaped by being beaten and stretched rather than melted and poured. The result is a metal that's exceptionally lightweight, hypoallergenic, and springy in a way that makes it comfortable for all-day wear. Sabae's titanium expertise is globally recognised; the region produced the world's first titanium eyeglass frames in the early 1980s, and the technique has been refined here ever since.
Cutting and Shaping
For acetate frames, the process begins with raw blocks or sheets being cut into rough frame shapes — fronts, temples, nose bridges — each as a separate component. For titanium and metal frames, individual parts are pressed from purpose-made moulds, one component at a time, with multiple pressing stages to gradually bring each part to its final shape without compromising the metal's structural integrity.
This is where the 200-step figure starts to make sense. A single pair of frames is not one object being worked on continuously — it's a collection of parts, each moving through its own sequence of processes, carried out by different specialists.
Hand-filing and fitting
This is the step that defines handmade acetate as genuinely handmade.
Once the front of the frame and the temples are shaped, their joints — the points where they connect — are finished with a handheld stick file. The goal is a perfectly flat, seamless join with no visible step between the two surfaces. No machine reliably achieves this. The file is guided by the craftsperson's eye and sense of touch, adjusting pressure and angle with each pass.
It's painstaking work. And it's the reason a well-made acetate frame feels like one continuous object rather than assembled parts.
Polishing
Polishing happens in stages, each using progressively finer materials. Early stages remove tool marks and shape irregularities. Later stages refine the surface further. The final stage uses a soft buff — traditionally a feather cloth — applied while the craftsperson assesses each individual frame by eye, adjusting pressure to account for the particular condition of that piece.
The result is the deep, glassy lustre characteristic of high-quality Japanese acetate. It can't be replicated with a single automated polish. The depth comes from the accumulation of stages, and from the fact that each frame is treated as its own object rather than a unit in a run.
Final inspection and adjustment
Before a Sabae frame leaves the factory, it's inspected and adjusted by hand. Hinges are checked. Temples are set to the correct angle. Nose pads are positioned. The whole frame is assessed for fit and finish.
Frames made in Sabae are well known among opticians for arriving already close to properly fitted — something that doesn't happen with mass-produced frames, which typically require significant adjustment before they're comfortable to wear.
What this looks like in practice: the brands that prove it
The process described above isn't an abstraction. It's what's behind every frame we carry at Sun of Japan. A few examples:
Masunaga is the brand whose founding family started the Sabae eyewear industry in 1905. More than a century later, the brand still makes its frames in the same city, to the same exacting standards. Handling a Masunaga frame is as close as you can get to understanding what the accumulated knowledge of 120 years of craft looks like in an object.
Factory900 takes acetate to structural places most makers won't attempt. Their frames involve deep beveling, three-dimensional layering, and curves that require dozens of individual hand steps to achieve. The rejection rate at the Factory900 workshop is deliberately high; frames that don't meet the standard don't leave. The ones that do are among the most technically demanding acetate frames made anywhere.
Matsuda frames can take up to two years from initial design to finished pair, passing through as many as 250 individual production steps. Each one is handcrafted in Sabae, where Matsuda has worked with the same specialist craftspeople for decades.
These aren't marketing claims. They're what the process demands when you refuse to cut it short.
Why it matters what's in your hands
There's a reason people who buy handmade Japanese eyewear rarely go back to anything else. The difference isn't subtle once you know what to look for; and once you've worn a well-made Japanese frame for a day, you start to feel it rather than just see it.
At Sun of Japan, every brand we stock is chosen because it represents that standard. Not because it's Japanese by origin alone, but because the craft behind it is real; done by hand, in Sabae, by people who have spent their working lives learning how to do it properly.
BROWSE MASUNAGA COLLECTION >
BROWSE MATSUDA COLLECTION >
BROWSE FACTORY900 COLLECTION >
Browse all brands at Sun of Japan
How Japanese eyewear frames are made by hand
Pick up a handmade Japanese frame and you notice something straight away. The weight is different — less of it, distributed more evenly. The surface has a depth to it, not the flat shine of something turned out by a machine. The hinges move cleanly. Even before you put them on, the frame tells you something was done to it that takes time.
That quality doesn't happen by accident. It's the product of a manufacturing process that involves over 200 individual steps, most of them carried out by hand, by craftspeople who have spent decades doing exactly this. Here's what that process actually looks like.
Where Japanese handmade eyewear comes from
Almost all of it comes from one place: Sabae, a small city in Fukui Prefecture on Japan's western coast. Sabae produces around 95% of all eyeglass frames made in Japan — a concentration of expertise that has no real equivalent anywhere in the world.
It started in 1905, when a local farmer named Gozaemon Masunaga; the same family behind the Masunaga eyewear brand stocked here at Sun of Japan; began teaching frame-making to the farming community as a way to earn income during Fukui's long, snowbound winters. The craft spread through the region, passed from family to family and factory to factory, and by the early 20th century Sabae had become Japan's undisputed centre of eyewear production.
What sets Sabae apart today isn't just history. It's the density of specialist knowledge; hundreds of small factories, each mastering one or two stages of the production process, working together in a system of shared craft that makes the finished frames possible.
The making process — step by step
Japanese frames are made from two main materials: acetate and titanium. The path from raw material to finished frame is different for each, but both share the same underlying commitment; that the critical stages are done by a person, not a machine.
The Material
Acetate is derived from natural cotton and wood fibres, compressed into dense blocks or sheets. It can be cut, layered, polished, and shaped in ways that synthetic plastics can't match — which is why it's the material of choice for brands that want colour depth, dimensional complexity, and a surface that improves with age. Brands like Factory900 and Masunaga have built their entire design languages around what acetate can do in skilled hands.
Titanium is a different challenge entirely. Cold-forged from wire at room temperature — no heat applied — it's shaped by being beaten and stretched rather than melted and poured. The result is a metal that's exceptionally lightweight, hypoallergenic, and springy in a way that makes it comfortable for all-day wear. Sabae's titanium expertise is globally recognised; the region produced the world's first titanium eyeglass frames in the early 1980s, and the technique has been refined here ever since.
Cutting and Shaping
For acetate frames, the process begins with raw blocks or sheets being cut into rough frame shapes — fronts, temples, nose bridges — each as a separate component. For titanium and metal frames, individual parts are pressed from purpose-made moulds, one component at a time, with multiple pressing stages to gradually bring each part to its final shape without compromising the metal's structural integrity.
This is where the 200-step figure starts to make sense. A single pair of frames is not one object being worked on continuously — it's a collection of parts, each moving through its own sequence of processes, carried out by different specialists.
Hand-filing and fitting
This is the step that defines handmade acetate as genuinely handmade.
Once the front of the frame and the temples are shaped, their joints — the points where they connect — are finished with a handheld stick file. The goal is a perfectly flat, seamless join with no visible step between the two surfaces. No machine reliably achieves this. The file is guided by the craftsperson's eye and sense of touch, adjusting pressure and angle with each pass.
It's painstaking work. And it's the reason a well-made acetate frame feels like one continuous object rather than assembled parts.
Polishing
Polishing happens in stages, each using progressively finer materials. Early stages remove tool marks and shape irregularities. Later stages refine the surface further. The final stage uses a soft buff — traditionally a feather cloth — applied while the craftsperson assesses each individual frame by eye, adjusting pressure to account for the particular condition of that piece.
The result is the deep, glassy lustre characteristic of high-quality Japanese acetate. It can't be replicated with a single automated polish. The depth comes from the accumulation of stages, and from the fact that each frame is treated as its own object rather than a unit in a run.
Final inspection and adjustment
Before a Sabae frame leaves the factory, it's inspected and adjusted by hand. Hinges are checked. Temples are set to the correct angle. Nose pads are positioned. The whole frame is assessed for fit and finish.
Frames made in Sabae are well known among opticians for arriving already close to properly fitted — something that doesn't happen with mass-produced frames, which typically require significant adjustment before they're comfortable to wear.
What this looks like in practice: the brands that prove it
The process described above isn't an abstraction. It's what's behind every frame we carry at Sun of Japan. A few examples:
Masunaga is the brand whose founding family started the Sabae eyewear industry in 1905. More than a century later, the brand still makes its frames in the same city, to the same exacting standards. Handling a Masunaga frame is as close as you can get to understanding what the accumulated knowledge of 120 years of craft looks like in an object.
Factory900 takes acetate to structural places most makers won't attempt. Their frames involve deep beveling, three-dimensional layering, and curves that require dozens of individual hand steps to achieve. The rejection rate at the Factory900 workshop is deliberately high; frames that don't meet the standard don't leave. The ones that do are among the most technically demanding acetate frames made anywhere.
Matsuda frames can take up to two years from initial design to finished pair, passing through as many as 250 individual production steps. Each one is handcrafted in Sabae, where Matsuda has worked with the same specialist craftspeople for decades.
These aren't marketing claims. They're what the process demands when you refuse to cut it short.
Why it matters what's in your hands
There's a reason people who buy handmade Japanese eyewear rarely go back to anything else. The difference isn't subtle once you know what to look for; and once you've worn a well-made Japanese frame for a day, you start to feel it rather than just see it.
At Sun of Japan, every brand we stock is chosen because it represents that standard. Not because it's Japanese by origin alone, but because the craft behind it is real; done by hand, in Sabae, by people who have spent their working lives learning how to do it properly.
BROWSE MASUNAGA COLLECTION >
BROWSE MATSUDA COLLECTION >
BROWSE FACTORY900 COLLECTION >
Browse all brands at Sun of Japan