Grid-cloth

The Workhorse of Diffusion Fabrics 💪

In the toolkit of a motion picture grip, Grid-cloth is one of the most essential and versatile materials for light modification. Its primary function is diffusion: to take a ‘hard’ light source (one that creates sharp, defined shadows, like the sun or a Fresnel lamp) and transform it into a larger, softer source that creates more pleasing, gentle shadows. This is achieved by stretching the fabric taut in a large metal frame and placing it in the path of the light.

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Properties and Strengths

Grid-cloth is prized for its specific characteristics:

• The Grid Pattern: Its most obvious feature is the grid of heavier threads woven into the fabric in a square pattern. This is a rip-stop design that gives the material exceptional strength and prevents small punctures from turning into large tears, even under high wind conditions on exterior shoots.
• Diffusion Quality: It provides a medium-heavy diffusion, effectively softening a light source while still allowing for a good amount of light transmission. It creates a beautiful, smooth field of light.
• Standardized Densities: To provide cinematographers with precise control, Grid-cloth is manufactured in several standard densities:
  • Full Grid Cloth: Offers the most diffusion.
  • Light Grid Cloth (or Half Grid): A medium, less dense version.
  • Quarter Grid Cloth: A very light diffusion for just taking the ‘edge’ off a hard source.

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On-Set Applications

The durability of Grid-cloth makes it the go-to choice for large-scale diffusion. Grip crews will stretch it on frames of all sizes, from a small 4x4’ frame to massive 20x20’ frames on exterior locations.

• Softening Sunlight: A common use is to fly a large frame of Grid-cloth over actors on a sunny day to soften the harsh overhead sun, creating a more flattering ‘open shade’ look.
• Creating Soft Boxes: It’s used as the front screen on large soft boxes (often called ‘rags’) built around powerful lights.
• Book Lights: It is often used as the diffusion layer in a ‘book light’ setup, where a light is bounced off a white surface and then passed through the Grid-cloth for an extra layer of softness.