Patterns such as concrete patterns, shading, and cross hatching are time consuming to place in a CAD file, cause the file to redraw more slowly, and take excessive disk space to store.
On District drawings, patterning should be used sparingly, and only when the meaning of the drawing or detail would not otherwise be clear. Often patterning is not required at all. Consultants should take care to limit the use of patterning and shading on District drawings.
The IPLOT software and District pen table provide a means to plot patterned or shaded areas on drawings without adding excessive elements to the file. See Pen Tables - Area Patterning for more information.
The following guidelines can be used to determine when and how to use patterning.
Use patterns only when the detail or drawing is not otherwise clear.
Use the minimum area of patterning that is needed to clarify the drawing.
Guidelines for using Linear Patterning
The use of linear patterning is also discouraged. Linear patterns break long lines into small pieces. It is very difficult to modify or measure a line that has been patterned. If an alternative to linear patterning is available to depict features, then the alternative should be used. For example, rather than labeling piping on a site plan by breaking the line and inserting text, it is better to place the text above or below the line, leaving the line of the pipe unbroken.
The District has provided custom line styles to be used in place of linear patterns. See the sections on Custom Line Styles for more information.