Photoshop’s very powerful type capabilities are centered on re-editable type layers, which you create using two of the four type tools. And Photoshop, being the versatile program that it is, also offers tools that enable you to make selections in the shape of letters, numbers, and symbols. The first article of this three-part series discussed the type options and features at your disposal. Understanding these features (the subject of this article) is your gateway to mastering text and type in Photoshop.
Type Basics: Type Layers and Anti-Aliasing
Type layers provide you the flexibility of re-editing text, even after you save, close, and re-open a Photoshop document. Type layers also permit you to add layer effects to dress up your type. When printing to a PostScript device (such as a laser printer or an imagesetter), type layers permit the text to be output as crisp, clean vector text. However, if you flatten your images or print to a non-PostScript device (such as an inkjet printer), you’ll need to understand anti-aliasing, how Photoshop treats the edges of non-vector text to ensure the best looking output.
Photoshop’s Type Layers
As long as type remains part of a type layer, it remains editable. You can return to the type layer at any time and make changes to the character and paragraph characteristics, or edit the text itself. After the layer is rasterized (or merged) or the image is flattened, the type can no longer be edited as type. (You can of course edit the pixels but you cannot, for example, highlight a word with the Type tool and overtype to correct a spelling error.)
In many ways, type layers are comparable to other non-background layers. Layer styles can be applied, type layers can be moved in the Layers palette, they can become part of a layer group, and adjustment layers can be applied. The Layers palette (see Figure 1) indicates what effects and adjustments have been applied to the type layers.
Figure 1 The appearance of the type is the result of the four layer effects applied to the type layer.
A type layer is always indicated by the letter T in place of a layer thumbnail in the Layers palette. Like other layers, you can click on the layer’s name and rename it. (By default, Photoshop names a type layer using the first characters of the layer’s content.) You can change the blending mode and opacity of a type layer and create layer-based slices from type layers.
Unlike other non-background layers, you cannot add pixels to a type layer. You cannot paint on a type layer, nor can you stroke or fill a selection. The adjustment tools (Blur, Sharpen, Dodge, Burn, Sponge, and Smudge) cannot be used on type layers.
Anti-aliasing is the process of adding transitional pixels along edges to soften the appearance of curves and diagonal lines. Because pixels are square, their corners stick out along curves, creating a jagged appearance – known as, of course, the jaggies. (Anti-aliasing isn’t required for vertical or horizontal lines because the edges of the pixels align.) These pixels are added in intermediary colors between the subject and the background colors. It is used with selection tools as well as type. Selection tools offer the option of anti-aliasing or not, but Photoshop’s type engine is more sophisticated, offering several levels of anti-aliasing. Because the appearance of type is usually critical, and because different fonts and type sizes have different requirements, Photoshop’s type engine offers Sharp, Crisp, Strong, Smooth, and None as anti-aliasing options.
Anti-aliasing makes curves and angled lines appear smoother by adding colored pixels along edges. Think of the transitional pixels as a mini-gradient, blending from the foreground color to the background color. When you look at black type on a white background, the added pixels are shades of gray (see Figure 2).
Figure 2 To the left, no anti-aliasing creates a case of "the jaggies."
The number 3 has no anti-aliasing applied, but the letter S is set to Crisp. The inset is at 100%, and the image behind is at 600% zoom.
At 100% zoom, the jagged edges of the character on the left (without anti-aliasing) are visible. With Crisp anti-aliasing, the curves appear smoother.
The colors used for the transitional pixels depend on the colors of the type and the background. For example, if the type is yellow (RGB 255/255/0) and placed on a background that’s blue (0/0/255), the transitional pixel colors could include (among others) RGB 80/80/175, 224/224/31, 192/192/63, and 144/144/111 (see Figure 3).
Figure 3 Anti-aliasing uses pixels that are a blend of the type color and the color below.
The differences among the four type anti-aliasing options are subtle. Even when zoomed to 1200%, it takes a close look to see variations. In Figure 4, the top row shows Sharp and Crisp, and the bottom shows Strong and Smooth.
Figure 4 Anti-alias options are subtly different.
In this particular example, the area of greatest variation is the left edge of the letter O. The Strong anti-aliasing (bottom left) is substantially darker than the others. Sharp (top left) and Smooth (bottom right) are nearly identical in both placement and coloring of the transitional pixels.
Keep in mind that anti-aliasing is not always a good idea. Very small type can become quite blurry onscreen when anti-aliased. Especially when preparing images for the web, think carefully about anti-aliasing. Using larger type, particularly the more linear sans-serif fonts such as Arial, can do far more to approve legibility and appearance than anti-aliasing. In addition, if the image is to be saved as a GIF or PNG-8 file, remember that anti-aliasing introduces several new colors to the color table, potentially increasing the file size.