Silicone Addition Colourless 5 – Very Soft Platinum Silicone for Masks & Flexible Moulds

Premium Very Soft Silicone for Professional Flexible Moulds

Silicone Addition Colourless 5 is a 2-component, platinum-cure (addition-cure) casting silicone with exceptional softness (Shore A 5) and very high elongation (>400%). This high-quality silicone combines very low viscosity (1,300 mPa·s) with excellent mechanical properties, specifically developed for highly detailed, flexible moulds and skin-friendly applications such as masks, props and body casting. Easy 1:1 mixing ratio and adjustable hardness by mixing with the Shore A 50 variant.

Key Benefits

• Exceptional softness: Shore A 5 for maximum flexibility and comfort in skin-contact applications
• Very high elongation: >400% elongation with 3 N/mm² tensile strength for durable, flexible moulds that do not tear
• Very fluid and self-de-airing: 1,300 mPa·s viscosity for perfect detail reproduction without vacuum treatment
• Platinum-cure technology: Minimal shrinkage (<0.1%), no inhibition on most substrates, long mould life
• Adjustable hardness: Mixable with Silicone Addition Colourless 50 for any desired hardness between Shore A 5 and 50
• Can be coloured: Transparent with a slight yellowish tint, easy to colour with silicone pigment

Typical Applications

• Masks and prosthetics for SFX, film, theatre and cosplay – skin-friendly and comfortable
• Props and flexible decorative elements for the entertainment industry
• Highly detailed candle moulds for artisan candle makers
• Body casting and lifelike impressions for art and medical simulation
• Soft, flexible soap moulds for artisan soap production
• Podiatry applications and medical models where softness is essential

Processing instructions:

1. Carefully mix components A and B in a 100:100 ratio (1:1 by weight) by hand or mechanically
2. Stir slowly in a figure-of-eight motion to prevent air entrapment
3. Process the mixture within the 30-minute pot life
4. Wait until fully cured before demoulding (3–6 hours at 20°C)
5. Curing can be accelerated by heat – every 10°C temperature increase roughly halves the time

Customisation options:

• Adjust hardness: Mix with Silicone Addition Colourless 50 for any desired hardness between Shore A 5 and 50. Example: for Shore A 18.5, mix 70% Shore 5 (35 g A + 35 g B) with 30% Shore 50 (15 g A + 15 g B)
• 
• Reduce hardness: Add silicone oil (note: migrates to the surface over time)
• Thicken for spreading: Add Silicone Thixo A or fumed silica
• Colouring: Use silicone pigment for intense colours

Silicones and More supplies high-quality silicones for professional mould making, SFX, body casting and flexible mould applications.

Important Warning: Inhibition in Addition-Cure Silicones

Note: This is an addition-cure silicone (platinum-cure). These silicones can be inhibited by sulphur, nitrogen, amino compounds and metal salts. If you are unsure whether the products you are using (including gloves, spatulas and cups) contain these ingredients, please do a small test first. These substances are found in many latex gloves, some plasticines, paints and adhesives, condensation-cure silicones, 1-component silicone sealants, natural rubbers and 3D printing materials (especially stereolithography). If you still wish to use these, you will need to apply a protective layer of polyvinyl alcohol (PVA).

Professional Support

Our technical specialists advise on material selection, hardness adjustments, processing techniques and optimal results for your specific flexible mould or mask application. Contact us for technical data sheets, processing guidelines or advice on preventing inhibition in addition-cure silicones.