See Also...304 512 ISOM Index Water and marsh index previous next
305 Crossable watercourse
A crossable watercourse, minimum 2m wide. The width of watercourses over 5m wide should be shown to scale.
Minimum line width 0.25mm
As ISOM 2000
Defined as symbol 305.0 in the default symbol set. This is a line object and can be drawn with any tool, use bézier mode if possible.
This symbol is drawn with a 0.25mm line (3.75m to scale), to represent watercourses of between 2m and 5m wide. For watercourses over 5m, the line should be drawn to scale. This means using lines of 0.33mm and upwards.
Stream: A natural watercourse with significant running water.
Cutting of streams in yellow
Blue symbols printed on yellow areas will naturally produce a green line. The way to overcome this is to have the blue colours cut (hold out) the yellows and this can be achieved in the colour table by setting the blue to zero ( "-1" for OCADv5) in the yellow separation column.
This creates a further problem of white gaps appearing if the colour registration is less than perfect. The colours should be trapped, but this facility is not easily available in OCAD. If you output using a high quality Desktop Publishing package, then trapping is possible. so....
Using a "-1" (OCAD5, use zero for OCAD7) in blue against yellow, to cut streams into open areas and thus prevent green lines, is debatable. Print quality has to be high as any mis-registration will cause white gaps in the yellow. The gap should be trapped, but OCAD does not normally allow trapping.
The lack of a trap has put off many, but Martin Green has an inspirational tip:- Define a new stream using the double line symbol, the inner blue cuts using a new blue colour, the outer, thinner blue edges do not cut, they overprint as normal! Brilliant.
This stream type has be incorporated into the Help Sheets ocd's available from Ashby Mapping.
Click to go to the top of this page