grain-overlay

name	grain-overlay
description	motion-graphic primitive — uniform noise texture overlaid with multiply blend mode at low opacity. signals "printed" / "shot on film" / "riso" feel. critical anti-AI visual cue across editorial and illustration packs.

grain-overlay

Purpose

Apply a subtle noise texture across the entire frame (or a specific layer) to give a printed / risograph / film-grain feel. The key anti-AI tell: AI-generated motion graphics often have perfectly clean fills; grain breaks that perfection.

Params

{
  "opacity": 0.08,                       // 0.05-0.15 range — subtle
  "blend_mode": "multiply",              // multiply | overlay | soft-light
  "texture_resolution": [1920, 1920],
  "tile": false,                          // tile small texture vs full-canvas
  "per_shape": false,                     // apply to each filled shape vs single overlay
  "seed": "static",                       // static (recommended) | per-frame (looks like noise filter)
  "intensity_blend_with_pack": true       // multiply by pack.micro_imperfection.grain_intensity
}

Behaviour

1. Render a PNG noise texture at texture_resolution.
2. Overlay on top of all content (or per shape if per_shape: true) with blend_mode and opacity.
3. Use a static seed — moving grain looks like a TV filter, not film grain.

Style pack overrides

• SP-C (editorial-cinematic) — opacity 0.05, multiply, full-canvas overlay.
• SP-G (riso-illustration) — opacity 0.12, multiply, per-shape (more aggressive printed feel).

Quality Checks

• Opacity ≤ 0.15 (more than that looks dirty).
• Static seed (not per-frame).
• Multiply blend mode (not normal — that would just be a gray overlay).

Failure Modes

• Grain looks like TV noise. Per-frame seed; switch to static.
• Grain too aggressive. Reduce opacity to 0.05.
• Grain invisible. Wrong blend mode; use multiply.