Are Injection Eyeglass Frames Always Cheaper Than Acetate Frames?

Understanding Material, Craftsmanship, and MOQ in Modern Eyewear Manufacturing

In the eyewear industry, many buyers assume that injection eyeglass frames are always cheaper than acetate frames. While this belief seems intuitive — given that injection molding is associated with mass production — the reality is more complex. The final cost of an eyeglass frame depends not only on the material type but also on the mold investment, processing method, surface finishing, and production scale. Understanding these differences helps optical brands, distributors, and B2B buyers make smarter sourcing decisions when working with an eyewear manufacturer or eyeglasses factory.

1. Material Differences: From TR90 to Acetate and Beyond

Injection eyewear is not defined by one single material. Manufacturers use a range of thermoplastics such as TR90 (Grilamid), Propionate, Acetate injection compounds, and even bio-based materials. Each of these materials comes with unique price points and performance characteristics.

• TR90: Lightweight, flexible, impact-resistant, and widely used in sports and everyday eyewear. The cost is moderate but the performance is excellent.
• Propionate: A cellulose-based plastic often used in designer brands for its glossy finish and color consistency.
• Acetate injection blends: Offer the look of acetate with easier mass molding capability, but material prices vary significantly.
• Bio-based polymers: Increasingly popular for eco-friendly eyewear, yet can be more expensive due to sustainable sourcing.

In contrast, acetate eyewear frames are made from layered sheets of cellulose acetate that are cut, milled, and polished manually or semi-automatically. This process allows for more vibrant color patterns, layered effects, and custom surface finishes that are difficult to replicate with injection molding.

2. Manufacturing Process: Molding vs. Hand Finishing

The production of injection eyeglass frames starts with designing and building a steel mold — a highly precise and expensive component that defines the frame’s shape and fit. Once the mold is made, the manufacturing process becomes extremely efficient. Molten plastic is injected into the mold cavity, cooled, and ejected as a complete frame front or temple piece. This method ensures high consistency and excellent scalability, which is why injection frames are often chosen for large-volume eyewear production.

On the other hand, acetate frames go through more manual steps — cutting, heating, shaping, tumbling, polishing, and assembling. Skilled craftsmanship plays a major role in ensuring quality and comfort. Each piece can have subtle variations that add to its character, making acetate eyewear more appealing to brands that emphasize design individuality or handmade quality.

3. Production Efficiency and Standardization

Once the mold is ready, injection eyewear factories can produce thousands of frames per day with minimal variation. This level of standardization makes injection frames ideal for OEM and ODM production where consistent quality is essential. In comparison, acetate frame production is slower, more labor-intensive, and requires highly skilled technicians.

However, efficiency does not always mean lower cost. When a client requests high-end injection frames with special surface treatments such as double-color painting, rubberized coating, or metal insert decoration, the cost can approach or even exceed that of standard acetate frames.

4. MOQ and Mold Investment

One major difference between injection and acetate eyewear lies in MOQ (Minimum Order Quantity). Since an injection mold typically costs around USD 2,000 or more, eyewear manufacturers usually require a production quantity of at least 1,200 pcs per design to make it economically viable. This is why injection eyewear suits large-scale B2B customers, private label brands, and retail chains that can support higher volumes.

For acetate eyewear, the MOQ can also vary depending on material supply. Non-standard color sheets often require ordering 30–40 kg or more from acetate suppliers, which may result in an MOQ of around 700 frames per color. In general, many eyewear factories — including ours — accept around 300 pcs per model as a standard MOQ for acetate production, offering greater flexibility for smaller optical brands.

5. Pricing Factors and Market Positioning

While injection frames are often associated with lower pricing, that is not always the case. High-end injection frames with intricate detailing, mirror coatings, or hybrid construction (metal + TR90) can command premium prices. Meanwhile, basic acetate frames produced at scale may actually cost less.

The key difference lies in design intent and target audience. Injection frames excel in mass production, brand consistency, and affordability for B2B clients. Acetate frames shine in texture, depth, and luxury feel — preferred by boutique eyewear brands or high-end optical shops.

6. It’s About Matching Product Type to Market Need

Whether an eyewear brand chooses injection-molded or acetate eyewear frames should depend on its business positioning, not just price. Injection frames offer superior scalability and uniformity for high-volume distribution, while acetate frames offer artistic flexibility and premium aesthetics.

At Shim Sight Eyewear, as a professional eyeglass frame manufacturer and supplier, we provide both injection and acetate eyewear solutions with OEM/ODM customization. Our factory supports low-MOQ production for acetate frames and efficient bulk manufacturing for injection models, giving our B2B partners the freedom to choose the most suitable path for their brand growth.

In short: injection frames are not always cheaper — the right choice depends on your material preference, design goals, and production strategy.