Editing PDF (section)

=== Vector graphics ===

As in PostScript, vector graphics in PDF are constructed with ''paths''. Paths are usually composed of lines and cubic [[Bézier curve]]s, but can also be constructed from the outlines of text. Unlike PostScript, PDF does not allow a single path to mix text outlines with lines and curves. Paths can be stroked, filled, fill then stroked, or used for [[clipping path|clipping]]. Strokes and fills can use any color set in the graphics state, including ''patterns''. PDF supports several types of patterns. The simplest is the ''tiling pattern'' in which a piece of artwork is specified to be drawn repeatedly. This may be a ''colored tiling pattern'', with the colors specified in the pattern object, or an ''uncolored tiling pattern'', which defers color specification to the time the pattern is drawn. Beginning with PDF 1.3 there is also a ''shading pattern'', which draws continuously varying colors. There are seven types of shading patterns of which the simplest are the ''axial shading'' (Type 2) and ''radial shading'' (Type 3). <!-- Pictures desperately needed here! -->