What your frame is made from affects its weight, flexibility and resilience. Discover the properties of the different materials used in sunglasses frames – and their benefits and disadvantages for you.
Sunglasses frames are made from materials that can be grouped into three main categories: classic materials; new generation materials; and natural or ecological materials. So, what are the advantages and disadvantages of these different materials for you?
Why should I choose a classic material?
Classic materials are those that have been used to make frames for several decades – which means they’ve had time to prove their worth. There are two types of classic material: metals and cellulose acetate.
• Metal was used to make the very first sunglasses and is still extremely popular thanks to the multiple ways it can be treated. Today, you can choose from metal frames with a brushed, anodised, shiny or matte finish. Corrective lenses can generally be fitted on a metal frame, although it is not recommended for very thick lenses.
o Benefits: highly resistant to impact, keep their form in hot temperatures
o Disadvantages: poor resilience, heavy, too rigid for sports, poor absorption of vibrations
• Cellulose acetate is a type of plastic made mainly from cotton fibre. Acetate frames were first produced in the 60s, and today you’ll find them in wide range of colours and forms. These frames are often considered the reference for sunglasses, as they have no downsides and can easily be used with corrective lenses.
o Benefits: very durable, solid and resistant, come in a wide range of colours and styles
What are the benefits of new generation materials?
If you’re looking for extra performance, especially for playing sports, you might want to consider new generation materials, which make the most of recent technology.
• Metal alloy frames first appeared in the 80s as a lightweight alternative to traditional metal frames. Unlike pure metal, they are also non-corrosive. However, some compounds may provoke allergies in certain people, which can cause a tingling or burning feeling around the nose, forehead or ears.
o Aluminium-based frames come in a range of colours.
> Benefits: flexible, lightweight
> Disadvantages: can cause allergies
o Titanium-based frames are usually a mix of titanium and copper/nickel.
> Benefits: extremely flexible (shape-memory), ultra-lightweight, available in frameless models, titanium is hypoallergenic
> Disadvantages: copper or nickel can cause allergies
• Polycarbonate is a tough, versatile plastic used to make frames for sunglasses and optical glasses. Because it is extremely resistant to shocks and heat, it is particularly recommended for sports sunglasses.
o Benefits: resilient, lightweight, durable, extreme resistance to shocks, resists temperatures up to 120°C
• Grilamid or nylon frames provide you with top-of-the-range performance. Unbreakable and capable of withstanding extreme heat, they are the ultimate sports sunglasses.
o Benefits: lightest plastic on the market, can’t be deformed by heat, most impact-resistant material available, exemplary resilience, repels water, excellent in all weather
On top of these new generation materials, you’ll find frames that take technology even further. The sunglasses market is continually innovating, working to make existing plastics even lighter, more flexible, more comfortable and with improved shape-memory. These hi-tech plastic frames are often designed for sportswear, as they combine unbeatable lightness with extreme resistance.
What are the ecological alternatives?
If you would like your sunglasses to be environmentally-friendly, the best choice is a frame made from natural or ecological materials. Production methods for these frames are more eco-friendly and result in lower greenhouse gas emissions.
• Biomaterial frames mix naturally-occurring biomaterials such as castor oil seed, hemp and sisal with plastic compounds (grilamid, polycarbonate, etc.) to produce a greener material.
o Benefits: eco-friendly, maintains properties of original plastic (flexibility, lightness, etc.)
o Disadvantages: still in its early days, so not widely available
• Recycled material can also be used to make frames. Like any form of recycling, the idea is to reuse materials that no longer serves their original purpose.
o Benefits: eco-friendly, maintains properties of original material
o Disadvantages: also maintains any weaknesses of the original material
• Natural materials such as wood or horn can be crafted into frames. The material is usually shaped by hand and the process requires considerable skill.
o Benefits: eco-friendly, usually one-of-a-kind
o Disadvantages: often fragile, less flexible, poor resistance to water