Custom Sunglasses Manufacturing Process: From Design Sketch to Finished Shipment

Custom Sunglasses Manufacturing at a Glance

4-6 weeks

Stock-shape custom frame, lead time

8-12 weeks

New mold + custom shape, lead time

$800-2,500

New mold cost (one-time)

100-300 pcs

MOQ with existing mold

$100-300

Pre-production sample round

AQL 2.5

QC standard for custom orders

Stage 1: Design & Design-for-Manufacturing Review

Everything starts with a render, and most renders are beautiful and unbuildable. That is not the designer's fault — it is simply that a screen does not enforce the physical rules a factory has to obey. This is where design-for-manufacturing (DFM) review earns its keep, and it is the step first-time brands almost always skip.

A frame that works has to clear three constraints at once: the lens has to seat into the front curve without gaps, the hinge boss has to be thick enough to be milled and to hold a screw, and the temple has to be thick enough to carry a metal core wire without splitting. A render can violate all three in one elegant swoop — a front curve that is too aggressive to take a standard lens, a hinge boss drawn as a thin sliver, a temple that tapers to a needle. The DFM review catches these before you pay for a mold.

What to send: a front view, side view, and top view, with dimensions in millimeters — lens width, bridge, temple length, and front curvature. If you have a reference pair, send it; a physical sample the factory can measure beats ten renders. A good factory replies with a marked-up drawing showing exactly where your design needs to change and why, and that back-and-forth is the single most valuable conversation you will have in the whole process.

Stage 2: Prototyping & Sampling

Before any bulk production, you approve a physical sample. For a stock-shape frame, the factory produces pre-production samples in your chosen material and color, usually 2-3 pairs, for $100-300 total. You hold them, wear them, bend them, and — most importantly — measure them against your spec.

This is where you spend money to save money. A sample round catches the mistakes that are cheap to fix now and catastrophic later: a color that reads differently in daylight than in the Pantone swatch, a temple length that is too short for the average head, a logo placement that looked right in the mockup but sits wrong on the curved surface. Fix it on the sample and it costs a conversation. Fix it after 5,000 pairs ship and it costs a recall.

The golden sample you approve is the contract. A sealed unit, kept by both sides, becomes the reference that settles every later argument about color, finish, and feel. Never skip the sample, and never approve it without physically holding it.

Stage 3: Mold Making (The MOQ Gatekeeper)

If your design uses a factory's existing frame shape, there is no mold stage at all — you move straight to production with the material, color, and logo you chose. That is the fastest, cheapest path, and it is the one I recommend to nearly every new brand.

If you need a genuinely new shape, the factory cuts a mold. A mold for a custom frame front costs $800-2,500 and takes 2-4 weeks. The mold is a steel cavity that forms the front — it is programmed from your CAD file, milled, polished, and tested with sample shots. The cost is dominated by the front's complexity: a simple round or rectangular front is cheap to machine; a front with a keyhole bridge, a stepped bevel, or an integrated hinge boss is expensive.

The mold is the real reason custom-shaped frames have a 500-1,000 pair MOQ. The factory is not being difficult — it is amortizing a one-time tooling cost across a production run, and below 500 pairs that cost lands hard on the per-unit price. Use an existing mold on order one; invest in a custom mold on order two or three, once you know your best-selling geometry.

Stage 4: Production & Assembly

Once the sample is approved and the mold (if any) is ready, bulk production begins. For an acetate frame, the sequence is: cut the sheet into blanks, CNC the front and temples, tumble-polish for 8-12 hours, insert the metal core wire and hinges, then assemble lenses and hardware. For TR90 it is injection molding followed by finishing; for metal it is stamping, soldering, and plating.

Bulk production for a stock-shape frame runs 2-3 weeks. A custom-shape frame adds time because the line has to be set up around your mold. The factory allocates line time based on order size and relationship — a 5,000-pair reorder from a returning customer gets scheduled before a 300-pair first order from a stranger, which is one more reason the second order is always smoother than the first.

This is the stage where you want the factory to communicate. A good factory sends photo updates of the first off-line units, and flags any variance against the approved sample before it becomes a batch problem. A bad factory goes silent and hopes you will not notice.

Stage 5: QC & Inspection

Quality control happens twice: in-process, as the factory checks units against the golden sample throughout the run, and pre-shipment, as a final inspection against a numeric standard. For a custom order, the standard is AQL 2.5 for major defects and 4.0 for minor, per ISO 2859-1 — which is a sampling plan that replaces opinion with a defined accept/reject number.

The lens is the most important thing to test. A UV400 lens must have transmittance below 1% across 280-400 nm, verified against EN ISO 12312-1, and a polarized lens should hit 99% polarization efficiency. A hinge should survive 10,000 open/close cycles without loosening. These are measurable, which means they are enforceable — and a spec sheet with these numbers is what turns \"the quality was bad\" into \"the lens failed the transmittance test, replace it.\"

For a first order, book an independent pre-shipment inspection ($250-350). An inspector who does not work for the factory opens the cartons, measures against your spec, and issues a report. It is the cheapest insurance you can buy against a five-figure order.

Stage 6: Shipping & Lead Times

Shipping closes the loop, and it is where first-time importers lose the most time because they did not plan for it. Air freight runs 5-7 days and is the right choice for a hard deadline or a first order you need to photograph. Sea freight runs 3-5 weeks and is far cheaper per unit, but it only makes sense on volume. Most custom orders under 1,000 pairs ship by air.

Build a 1-2 week buffer into every deadline. A customs hold, a typhoon delaying cargo out of Hong Kong, a holiday shutting the port for three days — these happen more often than anyone expects, and they always happen to the order with no buffer. The brand that orders six weeks before launch with a two-week buffer ships on time; the one that orders four weeks before launch with none is explaining the delay to their customers.

Put the whole thing together and a realistic plan looks like this: stock-shape frame, 4-6 weeks from approved design to your door. Custom shape with a new mold, 8-12 weeks. Double those numbers only if you change the design mid-process — which is the most expensive habit in the business, because every change re-opens a stage you already paid to close.

Frequently Asked Questions