> ## Documentation Index
> Fetch the complete documentation index at: https://comfytv.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Regrain

> Add realistic film grain with separate control over shadows, midtones, and highlights — for regraining a clean render or matching real film stock.

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  <img src="https://mintcdn.com/comfytv/dMkMxJDZdIo4YzAU/images/nodes/_placeholder.svg?fit=max&auto=format&n=dMkMxJDZdIo4YzAU&q=85&s=b54171099e5b02d4313fe581171ebbcc" alt="Regrain" width="800" height="450" data-path="images/nodes/_placeholder.svg" />
</Frame>

## What this node does

**Regrain** overlays synthetic film grain onto a clip. Unlike a flat noise pass, you set how much grain lands in the **shadows**, **midtones**, and **highlights** independently, plus its size and color saturation — mirroring how real film grain varies across the tonal range. This is the tool for a convincing organic film texture.

This is a rendered stage — it needs a **▶ Run** (torch/GPU backend). In goes `COMFYTV_VIDEO`, out comes `COMFYTV_VIDEO`.

If all three tonal amounts (`shadows`, `midtones`, `highlights`) are zero, the node passes the clip through unchanged (no grain to add).

To hand the result to a native ComfyUI node, insert a **Bridge**. See [bridges.md](https://github.com/jtydhr88/ComfyTV/blob/main/docs/bridges.md).

## When to use it

* Add organic film grain to a clean AI/CG render so it blends with real footage.
* Match the grain character of a specific film stock.
* Restore grain after denoising or upscaling flattened it out.

## Parameters

### grain\_size

`0.0`–`4.0` (step `0.05`), default `0.8`. Size of the grain particles. Smaller = fine, tight grain; larger = coarse, chunky grain.

### shadows

`0.0`–`1.0`, default `0.3`. Amount of grain in the darkest tones.

### midtones

`0.0`–`1.0`, default `0.15`. Amount of grain in the mid tones.

### highlights

`0.0`–`1.0`, default `0.05`. Amount of grain in the brightest tones. (Real film usually shows the least grain in highlights, hence the low default.)

### grain\_sat

`0.0`–`1.0`, default `0.4`. Color saturation of the grain. `0.0` is monochrome (luma-only) grain; higher adds colored grain.

### seed

`0`–`99999`, default `7`. Random seed for the grain pattern. Change it for a different grain distribution; keep it fixed for a repeatable result.

## Outputs

| Output    | Type            | Meaning            |
| --------- | --------------- | ------------------ |
| **video** | `COMFYTV_VIDEO` | The regrained clip |

## Tips

* Follow the film convention: most grain in shadows, less in midtones, least in highlights (the defaults already do this).
* Keep `grain_sat` low for a classic monochrome film-grain feel; raise it only if you want visible color noise.
* Set all three tonal amounts to `0` and the node does nothing (identity pass-through).

## Related nodes

* **Old Film** — full film-damage simulation (grain plus scratches, flicker, weave).
* **Video Stylize** — includes a simpler `grain` preset.