Contaflex GM3

The GM3 range of materials is particularly suited to fast machining in high volumes. That’s because GM3 is a terpolymer, based on high-purity glycerol methacrylate. Resultant lenses are durable, resilient to protein build-up and can be used for a variety of wearing regimens. Contaflex GM3 is available in two water contents: 49% and 58%.

GM3 technical information

Please Note: Regulatory requirements and standards vary from country to country, and are constantly evolving. As a global company, we want to be sure we provide you with detailed technical information, specific to your market, where appropriate, rather than using the condensed and simplified technical information on the website. If you need to use technical data for quality paperwork, or for a regulatory submission, please contact your account manager to obtain this precise and detailed information to support your regulatory requirements, we will be happy to help. 

Material characteristics

PropertyContaflex GM3 49%Contaflex GM3 58%
Classification Filcon l 2Filcon ll 2
USANAcofilcon BAcofilcon A
Oxygen permeability (ISO) @ 35°C gas to gas (barrers)15.925.5
Swell factor @ 20°C1.291.38
Water content by refractometer @ 20°C50%59%
Refractive index @ 20°C dry1.5221.523
Refractive index @ 20°C hydrated1.4161.402
Light transmission (%) @ 380-780nm>94%>95%
Hardness (Shore D)8788

Please note: These are typical values. Always check the certificate of conformity supplied with the goods for the actual values of the batch.

Environment control

For best manufacturing conditions Contamac recommends 19-23°C with a relative humidity of 45%-60%.


The recommended polishing compound is Contapol 2 with a spindle speed of 3,500rpm and weight of 240gms. With the above machining recommendations polishing should require a maximum of 30 seconds.


Hydration of GM3 materials is best performed in buffered saline with a pH of 6.8-7.3.

Manufacturing Consumables

  • High melt blocking wax
  • High melt blocking beeswax 
  • Kemdent blocking Wax
  • Water soluble wax
  • Contapol 1 polishing compound
  • Contapol 2 polishing compound
  • Cotton polishing cloth 
  • Delrin polishing cup
  • Delrin polishing sponge
  • Roller sponges


  • Tweezers
  • Glass vials
  • Stoppers
  • Aluminium top seals
  • Flip tear up seals
  • Shrink-wrap sleeves
  • Double soft lens mailers
  • Net vial sleeves
  • DMV soft lens remover
  • Lens catch mat


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