# Put an effect on the light only

Turn a light leak into ASCII characters, or run any effect on just the light, while your art stays clean on top.

Effects work on everything below them. So to change only a light leak, put the leak and its effects *under* your art. This recipe uses ASCII, and any effect works the same way.

## The stack

From the bottom up:

| Layer | Setting |
|---|---|
| Light Leak | Film › **Light** set to **Light only** |
| ASCII | Color › **Source color** at 100%, so the characters keep the leak's color |
| Your art | **Normal** for a logo or cutout, **Screen** for a full photo |

## Steps

1. Start with your art in Layers.
2. Add **Light Leak**. Drag it below your art in Layers.
3. In its faceplate, set **Light** to **Light only**. The leak draws its light with no picture under it.
4. Add **ASCII** and drag it between the leak and your art. Only the light turns into characters.
5. Select your art and pick its blend. Use **Normal** for a cutout that sits on top, or **Screen** for a full photo the light should glow through.

> TRY: Raise the leak's **Motion** and play the loop. The characters ripple as the light moves, and your art stays still.

## Why it works

An effect can only see what's below it. With the leak at the bottom set to Light only, ASCII sees nothing but light. Your art sits above both, so neither one touches it.

The same stack works for any pair. Try Light only under **Halftone** for printed light, or under **CRT** for light on a tube.