Frame material is the single largest driver of how a pair of glasses fits, lasts, and feels on the face. Patients pick frames by color and shape; opticians have to deliver fit, durability, and adjustability across a face shape, lifestyle, and skin chemistry that the patient often does not articulate. This guide compares the six material categories that account for the vast majority of dispensary stock: acetate, TR-90, titanium, stainless steel, monel, and wood. For each, what it weighs, what it adjusts to, what it withstands, and which patients it serves.
Cellulose acetate
Acetate is a plant-derived plastic (cellulose from cotton or wood pulp combined with plasticizers and pigments). It dominates fashion eyewear because color and pattern can be embedded into the material itself rather than applied as a surface coating, producing depth and richness no painted plastic can match. Most premium "designer" acetate frames are cut from billets layered with multiple colors that reveal as the frame is shaped.
Weight: Moderate. A typical acetate frame weighs 25 to 40 grams, similar to a stainless steel frame of the same size.
Hypoallergenic: Generally good. Acetate is rarely the cause of skin reactions. The hinges and core wires (often nickel-plated) are more common allergens than the acetate body.
Adjustability: Excellent with heat. Acetate softens at roughly 80 to 90 degrees C and can be reshaped repeatedly across the temples, nose pads (built-in saddle bridge styles), and end pieces. Cools and holds shape quickly. Salt-pan or warm-air heaters are standard equipment.
Durability: Acetate is moderately strong but can crack under sharp impact. Long-term, acetate slowly absorbs skin oils and can become slightly more brittle after years of wear. Quality acetate (mazzuchelli, mazzucchelli, or similar Italian-grade material) holds up far better than cheap acetate substitutes.
Cost: Wide range. Low-end injection-molded acetate runs $30 to $80 wholesale; cut-from-billet premium acetate is $150 to $400 wholesale and retails at the high end of the optical range.
Signature look: Bold, colorful, sculptural. Tortoise patterns, layered colors, chunky frames that make a statement.
TR-90 (thermoplastic polymer)
TR-90 is a flexible nylon-based polymer (thermoplastic polyamide) developed for sports eyewear and youth frames. It bends without breaking, weighs almost nothing, and resists impact. The trade-off is that the same flexibility that makes it durable also makes it harder to hold a precise adjustment.
Weight: Very light. TR-90 frames typically weigh 8 to 15 grams.
Hypoallergenic: Excellent. TR-90 is biologically inert and is one of the safest materials for chemically sensitive skin.
Adjustability: Possible but more demanding than acetate. TR-90 softens at higher temperatures (around 100 to 120 degrees C) and the optician must apply heat carefully because the material's flexibility can mask whether the bend is taking. Fine adjustments may spring back over time. Avoid the salt pan; use a hot air heater with controlled temperature.
Durability: Outstanding. Highly impact-resistant, will not shatter, returns to shape after most accidental bends. The preferred material for kids' frames, sports frames, and rough-use applications.
Cost: Low to moderate. TR-90 manufacturing is relatively inexpensive; most TR-90 frames sit in the value-tier price range.
Signature look: Sporty, lightweight, often in solid colors. Less variety in finish than acetate.
Titanium
Titanium is the premium metal frame material. It is strong, light, hypoallergenic, and corrosion-resistant. Two main grades appear in eyewear: pure (commercially pure) titanium and beta titanium alloy.
Pure titanium
Stiffer, holds shape well, harder to adjust. Used for full frames where rigidity matters more than flexibility. Hypoallergenic.
Beta titanium
Titanium alloyed with vanadium, aluminum, and other metals. Beta titanium retains titanium's biocompatibility (in most formulations) but adds spring and flexibility, making it easier to adjust and more comfortable on the face. Most "memory" or "flex" titanium frames are beta titanium variants.
Memory titanium / nitinol
A nickel-titanium alloy (nitinol) that returns to its original shape after deformation. Used for temple cores in flexible frames. Genuine memory titanium contains nickel, so it is not appropriate for nickel-allergic patients despite being marketed as hypoallergenic.
Weight: Very light. A titanium frame typically weighs 8 to 14 grams, comparable to TR-90.
Adjustability: Good for beta titanium with proper tools. Pure titanium requires more force and is unforgiving of sloppy bending. Use angling pliers designed for titanium; avoid sharp creases. Heat is not generally used for titanium adjustment.
Durability: Excellent. Corrosion-resistant in saltwater, sweat, and chemical environments. Will outlast the patient's prescription.
Cost: High. Wholesale typically $80 to $250 depending on grade and country of origin (Japanese titanium is the premium standard).
Signature look: Minimal, refined, often rimless or semi-rimless designs that take advantage of titanium's strength-to-weight ratio.
Stainless steel
Stainless steel frames are an alloy of iron, chromium, and small amounts of nickel and other metals. The chromium content makes them corrosion-resistant. Stainless is the workhorse middle-tier metal: cheaper than titanium, more durable than monel, and widely available.
Weight: Moderate. Stainless steel is denser than titanium; a comparable frame weighs 20 to 30 grams.
Hypoallergenic: Most stainless contains 8 to 10 percent nickel and can trigger reactions in nickel-allergic patients despite being labeled "stainless." Surgical stainless (316L) has lower nickel exposure. Patients with confirmed nickel allergy are safer in titanium.
Adjustability: Good. Stainless holds adjustments well and can be bent with standard angling pliers. More forgiving than titanium for technicians who are not regularly working in metal.
Durability: Strong, corrosion-resistant, holds plating and surface finish well. Not as fatigue-resistant as titanium under repeated bending.
Cost: Mid-range. Less expensive than titanium, more than monel.
Signature look: Clean, modern, available in many finishes (matte, polished, plated colors).
Monel
Monel is a copper-nickel alloy that historically dominated mid-tier metal frame manufacturing because it is inexpensive, easy to plate, and easy to adjust. It has lost ground to stainless steel because it is heavier, more allergenic, and less corrosion-resistant.
Weight: Heavier than stainless. Monel frames feel "substantial" on the face, sometimes too much for sensitive bridges.
Hypoallergenic: Poor. Monel contains 30 percent or more nickel and is one of the leading causes of metal allergy reactions in eyewear. Most plating contains additional nickel underlayers. Avoid for any patient with skin sensitivity.
Adjustability: Excellent. Monel is soft enough to adjust easily but holds the new shape. Forgiving for newer technicians.
Durability: Moderate. Plating wears off over time, exposing the base metal which then oxidizes to a green or black color. Sweat and humidity accelerate wear.
Cost: Low. Often the base metal in budget-tier frames.
Signature look: Classic, plated finishes, often imitating gold or silver tones.
Wood
Wood frames have a strong aesthetic following but limited functional fit. They are rigid, weigh more than acetate, and cannot be heat-adjusted in any meaningful way. Most "wood" frames are wood veneer over an inner plastic or metal core; pure-wood frames are rare and fragile.
Weight: Variable, generally heavier than acetate.
Hypoallergenic: Wood itself is inert, but finishes (lacquers, varnishes) and the underlying core (often metal) introduce the usual allergen risks.
Adjustability: Very limited. Wood does not respond to heat the way acetate does and breaks before it bends. Adjustments are limited to the metal hinge area and the temple core if present. Patients with non-standard face widths or pronounced asymmetry are poor candidates.
Durability: Moderate to poor. Sensitive to humidity, can warp, finishes scratch and chip.
Cost: Variable. Boutique wood frames carry high price tags driven by craftsmanship rather than functional performance.
Signature look: Distinctive, natural, conversational. Strong appeal to patients who want eyewear as an accessory statement.
Adjustment heat: acetate versus TR-90
Both acetate and TR-90 adjust with heat, but at different temperatures and with different timing. Acetate softens at 80 to 90 degrees C, holds the new shape almost immediately on cooling, and forgives small over-bending because the optician can re-heat and re-shape. TR-90 requires higher temperature (100 to 120 degrees C) and holds the shape less aggressively. A bend in TR-90 may relax slightly over the next few hours of wear.
The technical pitfall with acetate is over-heating, which causes the surface to bubble, lose color depth, or develop a haze. Use a salt pan or controlled-temperature air heater rather than a heat gun. The pitfall with TR-90 is under-heating, which causes the optician to apply force to a still-rigid material and stress the hinges or end pieces.
Patient match by use case
Pediatric (kids 5 to 14)
TR-90 first choice for impact resistance, light weight, and forgiveness of mis-handling. Avoid metal frames for active children because the hinges and bridges are stress points that crack under abuse.
Active adults and athletes
TR-90 for general sport. Wrap-style polycarbonate or grilamid frames for cycling, running, or impact sports. Beta titanium for daily wear that needs to survive a gym bag.
Senior patients
Light weight matters because of skin sensitivity and ear/nose tissue thinning. Beta titanium and lightweight acetate are both good choices. Avoid heavy monel frames that drag on thin nasal tissue.
Patients with nickel allergy
Titanium (pure or beta), TR-90, or quality acetate. Avoid monel, traditional stainless, and any "memory titanium" that contains nitinol unless the patient has tested fine with nickel-titanium previously.
Fashion-driven patients
Acetate for color and depth. Premium Italian acetate is the standard for the highest tier. Wood for the patient who wants to be the only one in the room with that frame.
Daily wear, all-purpose, long lifespan
Beta titanium for the patient who will keep one frame for five-plus years. Stainless steel for a more affordable but still durable mid-tier choice.
What to ask before recommending
- Skin reactions to costume jewelry, watch backs, or earrings? (Nickel allergy screen.)
- Active lifestyle, contact sports, work environment with chemicals or sweat?
- Has the patient had frames break in the past? Where?
- Backup pair available, or is this the only working pair?
- Sensitivity to weight on the bridge or behind the ears?
The ABO content outline expects working dispensers to identify materials by sight and recommend appropriate categories for patient lifestyle and chemistry. Patients defer to the optician's material recommendation more than they defer on lens choice; that trust depends on the optician knowing what each material actually does.