1.7.3 Tone Pattern Index

Tone pattern indexes contain information on both color and pattern. The last 3 digits specify the pattern index and all preceding digits specify the color. When the color is not specified (specification only by 3 digits), the foreground color (color index 1) is used.

The first of the three digits for the pattern index represent the pattern type.

0: Dot
1: Horizontal hatch
2: Right-up hatch
3: Vertical hatch
4: Left-up hatch
5: Cross hatch
6: Diagonal cross hatch

The second of the three numbers for pattern index specifies the dot size or line thickness with numbers from 0 to 5. Larger values indicate larger dots or thicker lines. The last digit specifies the density of the dots or diagonal lines with numbers from 0 to 5. Larger values indicate higher densities of dots or lines. No dots or lines are drawn for 0.

Pattern index 999 specifies a solid fill.

With color displays and printers, solid fill patterns with specified colors are often used. There is an option that will convert the color indexes into different pattern indexes for dot patterns so that the fill areas can be distinguished even when such programs are executed on environments that do not support color.

There are no patterns defined for integer values other than for the combinations above. Tone pattern tables are presented in Sections 8.1.4- 8.1.10.