How to Add Highlight Effects in Illustrator

Here is how you can add a background color highlight to text in Illustrator using the Appearance panel, based on the provided reference.

Adding a highlight effect in Adobe Illustrator can mean various things, from a simple background color block behind text to complex gradient glows or reflections. One common method, particularly for adding a colored background highlight to text, involves using the Appearance panel and effects.

A straightforward way to add a colorful background highlight to text directly within its appearance is by utilizing the Appearance panel and the Convert to Shape effect. This method keeps the highlight tied to the text object, making it easy to edit.

Here's a step-by-step guide based on the provided reference:

1. Add Text: Begin by adding a line or block of text onto your Illustrator canvas using the Type Tool (T).
2. Bring up the Appearance panel: Select your text object. Open the Appearance panel if it's not already visible by going to Window > Appearance. This panel shows all fills, strokes, and effects applied to the selected object.
3. Add New Fills: In the Appearance panel, locate the "Add New Fill" icon (it looks like a square within a square) at the bottom and click it twice. This will add two new fill attributes on top of the default character fill.
4. Arrange and Select the Lower Fill: In the Appearance panel stack, drag the lower of the two newly added "Fill" entries below the "Characters" or "Type" entry. This is crucial because effects are applied from top to bottom; placing the fill below the text ensures it appears behind your letters. With this lower fill selected in the panel, proceed to the next step.
5. Apply the Convert to Shape Effect: With the lower fill still selected in the Appearance panel, go to the main menu or the fx button at the bottom of the Appearance panel and choose Effect > Convert to Shape. Select a shape type, such as Rectangle or Rounded Rectangle. In the Convert to Shape dialog box, you can adjust settings like "Extra Width" and "Extra Height" to control the padding around your text for the highlight. Click OK.
6. Change the Fill Color: With the same lower fill still selected in the Appearance panel, click on its color swatch. Change the color to your desired highlight color, such as a bright green, yellow, or any color of your choosing.

This process creates a dynamic background shape behind your text that serves as a highlight. Because it's an effect applied via the Appearance panel, the highlight automatically adjusts if you edit the text content or formatting (like font size).

Summary Table:

Step	Action	Purpose
1. Add Text	Create text object.	Foundation for the highlight.
2. Open Appearance	Access Window > Appearance.	Manage fills, strokes, and effects.
3. Add Fills	Click "Add New Fill" icon twice.	Create layers for the highlight shape.
4. Select Lower Fill	Drag lower fill below "Characters"; Select it.	Position highlight behind text; Target for effect.
5. Apply Convert Shape	Effect > Convert to Shape (Rectangle/Rounded). Adjust padding.	Turn the fill into a shape based on text boundaries.
6. Change Color	Select fill swatch; Choose desired highlight color (e.g., bright green).	Define the visual appearance of the highlight.

This technique provides a flexible and non-destructive way to add a distinctive colored highlight behind your text in Illustrator.