> For the complete documentation index, see [llms.txt](https://animoia.gitbook.io/animoia-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://animoia.gitbook.io/animoia-docs/effects-reference/keying.md).

# Keying

Removes colors or tones to create transparency. Every effect below is listed in the sidebar, so you can jump straight to one. Return to [Effects reference](/animoia-docs/effects-reference.md) for stack behavior shared by all effects.

## Chroma Key

Makes selected colors or tones transparent with chroma key. Add it from **Effects > Keying** by double-clicking it or dragging it onto a compatible layer.

**Properties**

| Name              | Control | Visual or audible result                                                                                                                                        |
| ----------------- | ------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Key Color         | Color   | Sets the color used for the key portion of the result.                                                                                                          |
| Screen Gain       | Number  | Raises or lowers the brightness of this part of the image.                                                                                                      |
| Screen Balance    | Number  | Balances how the key judges the screen color against the other two channels. Adjust it when a green screen keys cleanly but a blue one does not, or vice versa. |
| Clip Black        | Number  | Raises the level below which the matte becomes fully transparent, clearing residual haze out of the keyed-out area.                                             |
| Clip White        | Number  | Lowers the level above which the matte becomes fully opaque, closing up thin patches in the subject.                                                            |
| Spill Suppression | Number  | Removes the screen color that has bounced onto the subject, taking the green rim off hair and shoulders.                                                        |
| Despill Bias      | Number  | Steers what the removed spill is replaced with, so de-spilled skin tones stay natural instead of turning magenta.                                               |
| Matte Shrink/Grow | Number  | Shrinks the matte inward to cut away a fringe, or grows it outward to recover an edge that was eaten away.                                                      |
| Matte Softness    | Number  | Blurs the matte edge so the subject blends into the new background instead of looking cut out.                                                                  |
| View              | Menu    | Switches the viewer between the final composite and the matte itself, which is how you check a key for holes and haze.                                          |

## Alpha Offset

Makes selected colors or tones transparent with alpha offset. Add it from **Effects > Keying** by double-clicking it or dragging it onto a compatible layer.

**Properties**

| Name        | Control | Visual or audible result                                                                                      |
| ----------- | ------- | ------------------------------------------------------------------------------------------------------------- |
| Quality     | Menu    | Changes edge smoothness and fine detail; higher settings produce a cleaner result but preview more slowly.    |
| Choke Matte | Number  | Grows or shrinks the matte, pulling the edge in to cut off fringing or pushing it out to recover a lost edge. |


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