Dense white diffusion fabric that scatters hard light into soft, even light with significant intensity reduction.
Technical Details
The material is made of reinforced ripstop nylon with a transmission of 12-18% compared to 25-35% for standard Silk. The reinforcing ribs are spaced horizontally and vertically every 5mm, achieving a tear strength of 45 kg/cm. Available in standard sizes from 6'×6' to 20'×20', with larger formats possible through heat-welded seams. The color temperature shift is minimal -50K in daylight, negligible with artificial light. Wind load calculation is performed with a factor of 0.8 compared to a closed surface.
History & Development
In 1983, Matthews Studio Equipment introduced the first Heavy Silk in response to demand for stronger light attenuation combined with diffusion. Cinematographer Conrad Hall first used the material extensively on "Road to Perdition" (2002) to achieve the characteristic soft illumination of interior scenes. Modern Grip & Lighting expanded the product range in 1995 to include ultra-heavy variants with up to 400 g/m². LED-optimized versions with improved UV resistance were launched in 2018.
Practical Use in Film
On "The Revenant," Emmanuel Lubezki used 12'×12' Heavy Silks to break up the harsh daylight in the forest scenes without losing the natural direction of the light. Typical workflow: positioning 2-4 meters above the set with a 30-45° tilt towards the main light source. Heavy Silk is particularly suitable for close-ups with high ISO values, as less additional light is needed. Disadvantage: The heavy material requires more stable grip equipment and at least Condor 40' lifts for large-format installations.
Comparison & Alternatives
Unlike standard Silk, Heavy Silk reduces light intensity by an additional stop while providing identical diffusion. Quarter Silk (1/4 Stop) and Half Silk (1.5 Stops) offer less attenuation, while Ultra Bounce combines reflection with diffusion. LED panels with softboxes are increasingly replacing large Silk installations, but do not achieve the uniform surface illumination of a 20'×20' Heavy Silk. For wind speeds over 25 km/h, Scrim Jim or solid diffusion panels are preferable.