# Constant

> Generate a solid colour image.

| Node | Constant |
|---|---|
| Menu | Color › Constant |
| **Names in each format** | |
| .oink comp (JSON) | `"type": "OC_N_constant"` |
| .nk script | `Constant` ([how .nk import works](/docs/nuke-users/nk-import)) |
| Python | `nuke.createNode("Constant")` |
| Assistant (MCP) | `create_node(type="Constant")` |
| Tab search | `constant` |

![Constant properties](/shots/nodes/constant@2x.webp)

## Inputs and outputs

| Port | Name | Type |
|---|---|---|
| output 0 | Image | image |

## Knobs

Panel tab **Constant**, in panel order.

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `channels` | channels | menu | `rgba` | rgba, rgb, alpha, all, none | `channels` |  |
| `color` | color | colour ×4 | `0, 0, 0, 0` | 0 to 1 | `color` |  |
| `format` | format | menu | `custom` | custom, HD_1080 (HD_1080 1920x1080), HD_720 (HD_720 1280x720), UHD_4K (UHD_4K 3840x2160), 2K_DCP (2K_DCP 2048x1080), 4K_DCP (4K_DCP 4096x2160), 2K_Super_35 (2K_Super_35 2048x1556), PAL (PAL 720x576), NTSC (NTSC 720x486), square_1K (squar... |  |  |
| `width_prop` | width | float | `1920` | 1 to 16384 (integer) |  |  |
| `height_prop` | height | float | `1080` | 1 to 16384 (integer) |  |  |

### Other knobs (Python, .nk and the assistant; not on the panel)

| Knob | Label | Type | Default | Range / values | .nk knob | Description |
|---|---|---|---|---|---|---|
| `gl_color` | Viewer Controls Color | float ×3 | `0, 0, 0` | 0 to 1 |  |  |
| `postage_stamp_frame` | Static Frame | int | `1` | -2147483648 to 2147483647 |  |  |
| `lifetimeStart` | Lifetime Start | int | `0` | -2147483648 to 2147483647 |  |  |
| `lifetimeEnd` | Lifetime End | int | `100` | -2147483648 to 2147483647 |  |  |
| `useLifetime` | Use Lifetime | boolean | `false` |  |  |  |
| `cached` | Cached | boolean | `false` |  |  |  |
| `bookmark` | Bookmark | boolean | `false` |  |  |  |
| `dope_sheet` | Dope Sheet | boolean | `false` |  |  |  |
| `clone_group` | Clone Group | string |  |  |  |  |
| `link_source` | Link Source | string |  |  |  |  |
| `link_overrides` | Link Overrides | string |  |  |  |  |
| `split_views` | Split Views | string |  |  |  |  |


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Sources: opencomp_core/nodes/color/constant.py, opencomp_electron/src/components/properties/knobSchema.ts, opencomp_core/nk/mapping.py