Photoshop® CS3 Channels and Masks Bible

Chapter 20. Masking Paths and Shapes

IN THIS CHAPTER

• Understanding vector objects

• Drawing paths

• Editing paths

• Working with the Paths palette

• Masking vector images

• Masking shapes

Paths and shapes are vector objects. They are mathematically defined curves. Vector objects are composed of anchor points and line seg-ments, known as Bézier curves. The advantage of using vectors is that they are resolution independent and when printed from Photoshop they retain their vector data, even though they are part of an image that contains pixels or raster information. This chapter explains the nature of vector-based objects in Photoshop, and how to make and mask them. There are two fun-damentally different methods used to create still images. Vector graphics are objects composed of mathematically defined points, curves, and shapes called objects. Raster images use a grid of colored squares, called pixels, to render variations of color.

Understanding Vector Objects

The shape of a vector object is composed of line segments and anchor points called paths. In Photoshop the Vector tools are used to draw and edit these objects that vectors are used for the following purposes:

• To make and store accurate selections.

• To create shapes.

• To create smooth lines.

• To stroke and fill areas.

• To mask layer content.

• To mask areas imported to other programs.

Working with vector objects is rather different than working with pixels, and the different techniques are quite independent of each other. You can't create, select, or edit ...