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MintSil (Firm) - Opaque Firm Silicone Rubber
MintSil (Firm) - Opaque Firm Silicone Rubber
MintSil (Firm) - Opaque Firm Silicone Rubber

MintSil (Firm) - Opaque Firm Silicone Rubber

Regular price $65.00 Sale

MintSil (Firm) opaque silicone rubber is a high quality silicone rubber suitable for creating moulds that require stability and firmness. It is also ideal for creating moulds with intricate details.

Moulds made with opaque silicone rubber are great for spotting bubbles in resin castings (as bubbles are more visible on a coloured surface) so you can easily pop or release them.

MintSil (Firm) has great bubble release and self-degases without the need for a vacuum machine. It is non-toxic, food-grade, skin-safe and safe to use indoors. Cures at room temperature.

If you are looking for an opaque silicone rubber with greater flexibility, check out our MintSil (Soft) Silicone Rubber.



Type: Platinum silicone (Addition-cure)
Colour: Mint (Opaque)
Mix Ratio:
 10:1 by weight
Potlife / Work time: 30 to 40 minutes

Demould: Approximately 3 to 4 hours (depending on volume mixed and temperature)
Hardness: Shore 40A (Firm)


Cure inhibition:

Please take note that all silicone rubbers may be subject to cure inhibition by contaminants on the surface of the master, or the material of the master being used for mould making. If your silicone rubber does not cure, there could be a chance that your master is reacting with the silicone rubber.

Materials that may inhibit the curing of platinum silicones are: Sulphur-based clay, tin-cured silicone rubber, latex rubber, some paint products, some 3D-printed plastic materials, etc.

Uncured rubber can be difficult to remove from your masters and may stain them. We recommend performing a small test on your master before making your actual mould.