3.2 Dimensions of map symbols

3.2 Dimensions of map symbols

It is recommended that an orienteering map is surveyed and drawn at 1:7,500 - twice the printing scale. Other reduction ratios may be used. When scribing, a 1:1 ratio is normal.
Dimensions in this book are given at the printed scale of 1:15,000.

The line widths are based on the micronorm pen sizes. All line widths and symbol dimensions must be held within 20% of their specified value. Deviations from the nominal value must only be used to improve legibility. Certain minimum dimensions must also be observed. These are based on both printing technology and the need for legibility:

MINIMUM DIMENSIONS

The gap between two fine lines of the same colour, in brown or black: 0.15 mm
The smallest gap between two blue lines: 0.25 mm
Shortest rock face symbol: 0.6 mm
Shortest stream or ditch symbol: 0.6 mm
Smallest bend in contour (spur or reentrant): 0.25 mm (from centre to centre of the lines)
Smallest area of marsh: at least two lines with a length of 0.5 mm
Shortest dotted line: at least two dots
Shortest dashed line: at least two dashes
Smallest area enclosed by a dotted line: 1.5 mm (diameter) with 5 dots
Smallest area of colour
- Blue, green, grey or yellow full colour: 0.5 mm²
- Black dot screen: 0.5 mm²
- Blue, green or yellow dot screen: 1.0 mm²

All features smaller than the dimensions above must be either exaggerated or omitted, depending on whether or not they are of significance to the orienteer. When a feature is enlarged, neighbouring features must be displaced so that the correct relative positions are maintained.

SCREENS

Vegetation, open areas, marshes, etc. are shown with dot or line screens. The following two tables list the permissible combinations of screens and the commercial availability of screens to meet the specifications. Some countries have produced special orienteering screens.

Abbreviations for the table:

s standard commercial photographic screen
@ special o-screen - available from IOF Map Committee through Harveys respectively.
LT Letratone screen
NT Normatone screen
t line thickness
ø diameter
s space between centres
d das length
g gap
a angle
f fill
r random dots

SYMBOL				1:15000		1:7500
Number		Colour	%	Lines		LT	NT	Dimensions
116	Broken ground	brown			@	88	250	ø0.35-0.5, r
210	Stony ground	black			@	na	251	ø0.25-0.35, r
211	Sandy ground	black yellow	10 50	24/cm 40/cm	s s	8 33	27-10 50-50	ø0.35, s0.9, a45°
212	Bare rock	black	30	54/cm	s	52	65-30
301	Lake infill	blue	50-100	40/cm	s	33	50-50
309	Uncrossable marsh	blue	50	20/cm	@	213	1010-50	t0.5, s1.0
310	Marsh	blue	33	27/cm	@	69	326	t0.25, s0.75
311	Indistinct marsh	blue			@	121	272	t0.25, s0.85 d1.8, g0.5
401	Open land	yellow	100
402	Open with scattered trees	yellow	42	12/cm	@	na	1160	ø0.8,s1.2, a45°
403	Rough open	yellow	50	40/cm	s	33	50-50
404	Rough open/scattered tree	yellow +white	50 42	40/cm 12/cm	s @	33 na	50-50 na	ø0.8, s1.2, a45°
406	Forest: slow run	green	20	40/cm	s	30	50-20
407	Undergrowth: slow run	green	17	14/cm	@	67	334	t0.25, s1.5
408	Forest: difficult to run	green	50	40/cm	s	33	50-50
409	Undergrowth: difficult to run	green	33	27/cm	@	69	954	t0.25, s0.75
410	Vegetation: impassable	green	100
412	Orchard	green yellow	30 100	12/cm	@	911	315	ø0.9,s1.6
413	Vineyard	yellow green	100		@		353	t0.4, s1.7, d2.6,g1.2
415	Cultivated land	yellow black	100 5		@	915	205	ø0.5, s1.8
501	Road infill	brown	50	40/cm	s	33	50-50	t2.25, f1.55
502	Road infill	brown	50	40/cm	s	33	50-50	t1.7, f1.0
503	Road infill	brown	50	40/cm	s	33	50-50	t1.3,f0.6
528	Settlement alternative	yellow +green black	100 50 33	40/cm 27/cm	s s	33 69	50-50 326	t0.25,s0.75
529	Out of bonds	black	33	13/cm	s	924	226	t0.5, s1.5
530	Parking area	brown	50	40/cm	s	33	50-50

s	standard commercial photographic screen
@	special o-screen - available from IOF Map Committee through Harveys respectively.
LT	Letratone screen
NT	Normatone screen
t	line thickness
ø	diameter
s	space between centres
d	das length
g	gap
a	angle
f	fill
r	random dots