# Fix the symbol, and the whole map follows

> The fence you drew last night has the wrong ticks, and so does every fence on the sheet. Here is what you can do about it without leaving the tab the map is in.

Andrey Surzhikov · 2026-08-11 · https://gratic.app/articles/symbol-editor

The fence you drew last night has the wrong ticks. Not wrong in your drawing, wrong in the symbol
itself: the spacing is too tight for this map, and every fence on the sheet has it.

Editing the symbol is not the hard part. OCAD has kept a symbol editor behind a right click for decades,
and any mapper reading this has used it. What is worth a paragraph is where that editor lives here: in
the same browser tab as the map, on whatever computer you happen to be sitting at, with the fences
redrawing under the dialog while you type the number.

_[The symbol card open over the map: the drawing canvas on the left, the symbol panel on the right, and the properties of the selected symbol above it.]_

## The standard is already in the document

A new map is not an empty box waiting for you to find a symbol set. The symbols and the inks of ISOM
2017-2 are in the document from the moment you create it, and you find a symbol by typing its number or
its name.

Nothing to download, nothing to install, nothing to point the program at. The sets for sprint, mountain
bike and ski orienteering are there the same way.

_[The symbol panel: the set name at the top, a search field for code or name, and a grid of real ISOM symbols under it.]_

## The symbol picks the tool

Choose a contour and you are drawing a smooth curve. Choose a building and you are drawing right angles.
You do not reach for the toolbar between symbols, because the symbol already knows what it is made of.

This sounds small until you have drawn two hundred buildings.

## Change the symbol, not the objects

Make the footpath a little wider and every footpath on the map is a little wider. The objects on your map
hold a symbol code, not a copy of the symbol, so the drawing follows the definition.

That is the whole point of drawing with a symbol set rather than with a pen, and it is why the next two
sections are worth reading: everything you change there lands on the map at once.

**Change the symbol and every object drawn with it follows, because your map holds symbol codes rather than copies**

## Lines and areas are made of fields

A line symbol is a set of numbers you can see and change: dash length, gap, how many dashes to a group,
the width and colour of the casing. An area symbol is the same: hatching angle, line width, spacing, or
a pattern laid on a grid.

The ruined fence is dashes plus a repeated element. The uncrossable marsh is blue hatching at a spacing
you set. You are not rebuilding the symbol from scratch to move a line half a millimetre.

If you would rather see the card than read about it, [open a map in Gratic](https://my.gratic.app) and
pick a line symbol from the panel.

_[A line symbol open for editing: the dash length, the gap, how many dashes to a group, and the block for the element repeated along the line.]_

_[An area symbol open for editing: hatching with its colour, line width and spacing between lines.]_

## The drawing inside the symbol is yours to draw

What repeats along a line and what sits inside a pattern is a small drawing, and you make it by hand on
a field of ten millimetres either side of zero, with a millimetre grid under it.

There is a pen, a rectangle, a circle. There is union and subtraction, so a boulder cluster is three
circles joined rather than three circles hoping to stay together. Position, size and rotation are typed
in millimetres, because that is what the printed sheet is measured in. And there is undo, which matters
more than it sounds when you are nudging a glyph by tenths.

**What repeats along a line and what sits inside a pattern is a small drawing, and you draw it by hand on a millimetre grid**

_[The glyph canvas: a millimetre grid with two axes crossing at zero, a scale bar, the drawing tools down the side, and the shape being edited in the middle.]_

## The inks belong to the set

Colours here are inks, not screen colours. You add one, set it in CMYK, mark it to overprint, and move it
up or down the print order. Move an ink and the map redraws in that order, because the order of the inks
is what a printing press actually does with them.

Within a layer the ink order decides what covers what. That is the rule an orienteering map is built on,
and it is why the colour table is a table rather than a palette.

_[The colour table: the inks in print order with arrows to move them, the overprint checkbox, and the note that the top of the list draws on top.]_

## A set you can start, borrow or swap

A set belongs to a layer rather than to the map, so a club set on one layer and the standard set on
another sit in the same document without their numbers colliding.

You can start a layer with an empty set and build it symbol by symbol. You can open somebody else's map
and keep their set: files from OCAD and OpenOrienteering Mapper come in with their symbols, and the
import shows you which of them it recognised before anything lands on your map.

And you can change the set on a layer you have already drawn on. The conversion lists every symbol the
layer really uses, with the number of objects behind it, and asks what each one becomes. It is one step,
so one undo puts it back.

**A symbol set belongs to the layer, so a club set and a standard one live in the same map without colliding**

_[Changing a layer from one symbol set to another: the symbols the layer uses on the left with object counts, the assigned symbols on the right, and the Convert button.]_

## All of it in a browser tab

There is nothing to install and no licence to move between machines. The symbol editor, the colour table
and the glyph canvas open in the tab where the map is, on whatever computer you are sitting at.

If you draw for a club, that also means the set travels with the map rather than with the person who has
the right version of the software.