The 9-slice scaling option in Adobe Illustrator CS5 gives users greater control in how symbols appear in a document when they are scaled. Rather than simply increasing or decreasing the size of the symbol as a whole, users can specify which portions of the symbol will change and which will remain static. For example, if you want to increase the size of a button created in Illustrator, you can increase the dimensions of the button while leaving text inside the button the same size.
The Nine Slices
- When you enable 9-slice scaling, a grid appears over the symbol. The grid divides the symbol into nine areas, or slices, by dotted lines. There are four vertical lines, and four horizontal lines, making three columns and three rows, much like a tic-tac-toe board. The slices in the center row will scale vertically, but not horizontally. The slices in the middle column scale horizontally, but not vertically. The center slice will scale horizontally and vertically. The four corner slices will not scale at all.
Scaling and Symbols
- Before you can use 9-slice scaling, you need to create a symbol, or convert an object or group of objects into symbols. You can do this by using the Selection Tool to highlight an object or group of objects, then pressing the “F8” key to open the Symbol Options dialog box. For example, if you have made a button from a rectangle with a text box inside it, you could select both and transform them into a symbol.
Activating 9-Slice Scaling
- You can activate 9-slice scaling by clicking the “Enable Guides for 9-Slice Scaling” in the Symbols Options dialog box when you create a symbol, or by double-clicking a symbol in the Symbols Panel. You can make changes in the nine slices at any time by double-clicking the symbol on the art board, which puts the symbol in “Edit (Isolation) Mode.” Once you have enabled 9-slice scaling, any changes in the size of the symbol will be restricted by the grid.
Using 9-Slice Scaling
- Using the example of a rectangle containing text inside it, you can position the 9-Slice Scaling Guide so that the text is in one of the corners of the guide. When you increase or decrease the size of the rectangle, the text will be unaffected. If you place the text in a center row of the grid, its height can be scaled but not its width. If you place it in the center column, the width can be scaled but not the height.
