What Do the Numbers and Letters on Kids Optical Frame Temples Mean?

Those tiny codes on kids optical frame temples confuse many buyers I talk to. Order the wrong size once, and a whole container of frames may not fit your market. On our production line in Taizhou, we stamp these markings for a reason — and once you can read them, sourcing becomes far less risky.

The numbers and letters on kids optical frame temples show the frame’s size, model, color, and material. A code like 48□16-130 means 48 mm lens width, 16 mm bridge width, and 130 mm temple length. Letters usually identify the model number, color code, or material such as TR90.

Let me break each part down. I will show you how to read the size code, what the material stamps mean, and how to use both when you source children’s frames.

How Do I Read the Size Numbers Stamped on Kids' Optical Frame Temples?

During a QC check last spring, a new inspector flagged a batch because the temple stamp read 46□15-125 instead of the sample's 48□16-130. That catch saved a client's launch — the two sizes fit very different age groups.

Read the three-number code as lens width, bridge width, and temple length, all in millimeters. In 48□16-130, the lens is 48 mm wide, the bridge is 16 mm, and the temple arm is 130 mm long. The small square is only a separator, not a measurement.

The three numbers are the heart of the marking. They follow a global convention, so a 48□16-130 frame from our factory can be compared directly with a frame from any other supplier. Here is what each number tells you.

The Three Core Measurements

For reference, adult frames often run 52-18-140 — meaning a 52 mm lens width, 18 mm bridge, and 140 mm temple. Kids' frames sit at the smaller end. General eyewear lens widths span roughly 40 mm to 60 mm, and temple lengths commonly fall between 120 mm and 150 mm, with children's frames skewing shorter.

The Boxing Symbol

That little square between the first two numbers is called the boxing symbol. It signals that the lens width was measured using the Boxing System ¹ — an imaginary rectangle drawn around the lens. Many buyers assume it hides a fourth measurement. It does not. It is simply a standardized separator.

One nuance we always share with clients: check both sides of the frame. Some brands stamp size data on one temple and put the model number and color code on the other. A few designs place the bridge size ² on the bridge itself. Never assume one temple tells the whole story.

What Do the Material Markings Like TR90 or TPEE Tell Me About Frame Quality?

Flexibility versus stiffness is the trade-off we weigh on every new kids' style. A rigid frame holds lenses precisely but snaps under abuse. That is exactly why we mold most of our children's frames in TR90 and TPEE — and stamp those names on the temple.

Material markings like TR90 or TPEE identify the polymer used in the frame. TR90 is a lightweight, flexible nylon that resists snapping. TPEE is a softer elastomer often used for temples. Both signal a durable, child-safe frame rather than brittle standard plastic.

Material stamps are quality signals, and they matter more on children's frames than anywhere else in eyewear. Kids twist, sit on, and drop their glasses daily. After 15 years of making children's eyewear, we treat the material marking as a promise to the buyer.

Comparing the Common Material Codes

A popular build we produce combines a TR90 front with TPEE temples. The front stays dimensionally stable so the lenses hold their optical position, while the temples bend past 90 degrees and spring back without permanent deformation. One of our two-tone styles — a glossy black TR90 front with navy TPEE temples ending in soft sky-blue silicone ear tips — shows this pairing in action.

Safety Marks Beyond the Material Name

Buyers in Europe, Australia, and Japan increasingly ask about more than flex. Hypoallergenic and chemical safety marks ³ — confirming frames are free from BPA, phthalates, and lead — are emerging on children's temples because toddlers chew on them. For sports eyewear, impact-resistance ratings such as ASTM F803 ⁴ certify frames for high-velocity impacts. If a supplier cannot explain what their material stamp means, treat that as a red flag. We supply material documentation with every OEM order because serious brands need it for import compliance.

Why Should I Care About These Codes When Sourcing Frames From a Manufacturer?

A procurement manager from Australia once emailed us photos of a competitor's temple stamps, asking us to decode them before she placed her first order. That conversation convinced me every buyer should learn this skill before signing a purchase order.

Temple codes let you verify sizes, compare frames across suppliers, confirm materials, and reorder accurately. Without reading them, you risk buying frames sized wrong for your market, mismatched replacement stock, or materials that fail your country's child-safety requirements.

Here is a tension worth addressing honestly. Some buyers treat the printed numbers as the final word on fit. Others argue the numbers barely matter because real fit depends on frame shape. Both extremes cause problems. My position, built from exporting to 20+ countries: the codes are your screening tool, and real-world fit testing is your confirmation. You need both.

What the Codes Do for You as a Buyer

1. Verify production consistency. When we run QC in our 5S-managed workshop, inspectors check that stamped sizes match the approved sample. You should do the same on arrival inspection.
2. Compare across suppliers. A 47□16-128 from one factory and another can be compared on paper before you pay for samples.
3. Reorder without guesswork. The model number and color code let you repeat an exact SKU months later — critical when a style sells well.
4. Prove compliance. Material stamps and marks like CE support your customs paperwork and retailer audits.
5. Plan a size ladder. With around 800 existing styles in our catalog, buyers use size codes to build a coherent range — say, 44 mm eye sizes for toddlers up to 49 mm for tweens — without investing in new molds.

The objection I hear most: "Can't I just eyeball the frames?" You can, until you receive 5,000 units and discover the bridge size is 2 mm off for your market's typical nose profile. Two millimeters at the bridge changes where the entire frame sits. The codes exist so you never rely on eyeballing alone.

How Can I Use Temple Markings to Choose the Right Fit for Different Age Groups?

Early in our export history, we learned a hard lesson: a European client ordered one size for ages three to ten. Returns taught us that children's faces change too fast for one-size thinking, and the temple codes are how you plan around that.

Match the size code to the age group: roughly 39–43 mm lens width for toddlers, 44–47 mm for ages four to seven, and 47–50 mm for ages eight to twelve. Prioritize bridge width and temple length, since these determine stability on a growing face.

Sizing children is different from sizing adults. An adult's face is stable; a child's face is a moving target. So pediatric eyewear fitting starts with the codes but must account for growth, nose development, and ear position.

A Practical Size Guide by Age

Treat this as a starting map, not law. The temple length number is helpful but not absolute — frame curvature, ear-hook design, and material flexibility all change how a frame actually sits. One of our translucent pale-pink acetate styles fits slightly larger than its stamped code suggests because of its rounded rectangular geometry and softer curve at the tips.

Which Numbers Matter Most for Kids

Bridge width comes first. Young children have low, undeveloped nose bridges, so a bridge that is 1–2 mm too wide slides constantly. Temple length comes second. Too short, and the arm digs in behind the ear; too long, and the frame slips forward during play. Lens width matters mainly for coverage — the child’s pupillary distance should sit near the optical center of each lens, which your optician partners will confirm during dispensing.

Also look for design features noted in the model number or spec sheet. Spring hinges forgive the outward pulling kids do when removing glasses one-handed. Curved, adjustable ear hooks — like the embossed silicone tips we mold on our two-tone TPEE temples — add grip for active wear. Some suppliers even use growth-adaptive sizing codes for fit-to-grow designs, where temple tips can be adjusted or swapped as the child's face matures. Build your range across at least two or three size steps, and use the stamped codes to keep each step consistent from order to order.

الخلاصة

Temple codes tell you a frame's size, model, color, and material at a glance. Learn to read them, verify them at inspection, and pair them with real fit testing — that is how confident kids' eyewear sourcing works.

ملاحظات ختامية

1. ISO 12870 specifies the requirements for spectacle frames and the application of the boxing system. ↩︎

2. The FDA regulates the design and sizing of medical devices like eyewear to ensure proper fit. ↩︎

3. European customs regulations require specific safety markings and chemical compliance for imported children’s products. ↩︎

4. ASTM F803 is the standard specification for eye protectors used by players of various sports. ↩︎