The following suggestions are useful for creating line patterns.
• When a stream line is symbolized with a pattern, the symbolization process tries to fit the pattern along the entire length of the line.
• When a point to point line is symbolized with a pattern, the pattern is fitted between each pair of significant points on the line. This often results in dashes touching each other at the points on the line, or excessive spaces at these points. This becomes most obvious when a stream line has been approximated using a point to point line. To avoid this problem, stream type features (e.g. rivers) which will be symbolized as dashes must be digitized as stream lines. If you must represent stream type features as point to point lines, then use the /TOL qualifier to specify a large tolerance for checking significant points.
• Identify whether or not the pattern will require, or ever be used in, a closed loop or polygon. If so, the beginning and ending pattern of the line are usually mirror images. For example, when symbolizing an open line with a pattern of dashes, the symbolized line will begin and end with a full dash. However, if the line forms a closed loop, then it will begin and end with a half dash which looks like a full dash spanning the beginning and ending point.
• When digitizing closed loops you must enter the first point twice: once at the start of the figure and once at the end. This closes the figure. You can press the C key to automatically close a line you are entering. The line will be stored with characteristics that enable half start/stop dashes as described above.
• If the beginning pattern in a pattern definition contains a blank or dash command, a half space or dash will be placed leading into and away from each significant point in a line. If the beginning pattern does not contain a blank or dash command, half dashing and spacing is not used to symbolize the line.
• When creating a pattern definition, identify the start and end of the pattern first, and then fill in the remainder.
• If a pattern should have a distinguishing feature (such as an anchorage symbol) which is to be placed before or after a dash or blank, determine whether or not its location is critical. For example, should it always be vertical, or should its orientation reflect the direction of the line being symbolized.