Illustrator comes with many patterns that you can access in the Swatches panel and in the Illustrator Extras folder on the Illustrator CD. You can customize existing patterns and design patterns from scratch with any of the Illustrator tools. Patterns intended for filling objects (fill patterns) differ in design and tiling from patterns intended to be applied to a path with the Brushes panel (brush patterns). For best results, use fill patterns to fill objects and brush patterns to outline objects.

When designing patterns, it helps to understand how Adobe Illustrator tiles patterns:

• All patterns tile from left to right from the ruler origin (by default, the bottom left of the artboard) to the opposite side of the artwork. To adjust where all patterns in your artwork begin tiling, you can change the file’s ruler origin.

  note: Ruler origin in CS5 is different from that in CS4. As a result, the appearance of tiling patterns may not match when you copy-paste objects from CS4 to CS5. For such objects, tiles can be transformed using the Transform panel to match the CS4 appearance.

• Fill patterns typically have only one tile.

• Brush patterns can consist of up to five tiles—for the sides, outer corners, inner corners, and the beginning and end of the path. The additional corner tiles enable brush patterns to flow smoothly at corners.

• Fill patterns tile perpendicular to the x axis.

• Brush patterns tile perpendicular to the path (with the top of the pattern tile always facing outward). Also, corner tiles rotate 90° clockwise each time the path changes direction.

• Fill patterns tile only the artwork within the pattern bounding box—an unfilled and unstroked (non-printing) rectangle backmost in the artwork. For fill patterns, the bounding box acts as a mask.

• Brush patterns tile artwork within the pattern bounding box and protruding from or grouped with it.

Guidelines for constructing pattern tiles

Follow these general guidelines for constructing pattern tiles:

• To make the pattern less complex so that it prints more rapidly, remove any unnecessary detail from the pattern artwork, and group objects that are painted with the same color so that they are adjacent in the stacking order.

• As you create your pattern tile, zoom in on the artwork to align elements more accurately, and then zoom out from the artwork for the final selection.

• The more complex the pattern, the smaller should be the selection used to create it; however, the smaller the selection (and the pattern tile it creates), the more copies are needed to create the pattern. Thus, a 1‑inch-square tile is more efficient than a 1/4‑inch-square tile. If you are creating a simple pattern, you can include multiple copies of the object within the selection intended for the pattern tile.

• To create simple line patterns, layer stroked lines of varying widths and colors, and place an unfilled, unstroked bounding box behind the lines to create a pattern tile.

• To make an organic or textural pattern appear irregular, vary the tile artwork subtly for a more realistic effect. You can use the Roughen effect to control variations.

• To ensure smooth tiling, close paths before defining the pattern.

• Enlarge your artwork view and check for flaws before defining a pattern.

• If you draw a bounding box around the artwork, make sure that the box is a rectangle, that it is the backmost object of the tile, and that it is unfilled and unstroked. To have Illustrator use this bounding box for a brush pattern, make sure that nothing protrudes from it.

Follow these additional guidelines when creating brush patterns:

• When possible, confine artwork to an unpainted bounding box so that you can control how the pattern tiles.

• Corner tiles must be square and have the same height as side tiles to align properly on the path. If you plan to use corner tiles with your brush pattern, align objects in the corner tiles horizontally with objects in the side tiles so that the patterns tile correctly.

• Create special corner effects for brush patterns using corner tiles.

Create pattern swatches

Create seamless geometric patterns

Construct irregularly textured patterns

Create corner tiles for brush patterns

Corner tiles lend special border effects when applying brush patterns. You can create corner tiles from scratch, or you can use a brush pattern’s side tile as the basis for designing complementary outer and inner (reflected –135°) corner tiles.

Modify patterns