If we wish to create very precise drawings in order to export to a CAD program, for example in textiles design, using Adobe Illustrator's grid functions can greatly assist.
The first step is the creation of a new document within Illustrator, establishing the width and height of the document. We are presented with a drop-down list of various Preset page sizes - these can be for either Print or Web output. In the former we would use millimeters or centimeters; in the latter case, we would use pixels as the unit of measurement.
If we wish to set these units as our default measurements we would open the top Edit menu and choose Preferences. If using Illustrator on the Apple Macintosh platform, there is a slightly different location, namely the top Illustrator menu. Next select Preferences and Units and change the General option to millimeters.
In order to view the document grid, we would select from the View menu the option of Show Grid. If you like keyboard shortcuts you could press the Control key (PC) and the semi-colon key. On the Macintosh platform, we would use the Command key. Doing so will make visible Illustrator's default grid which is 25.4mm and 8 subdivisions. This odd number value is simply the metric equivalent of an inch, reflecting the fact that Illustrator is an American program which uses the older Imperial measurement system. Since only three countries in the world use the Imperial system, most Illustrator users will have to alter their units of measurement.
Therefore, to change our visible grid, go again to the Edit menu and choose Preferences (or Macintosh users go to Illustrator and Preferences), and select Guides & Grid. Change the entry for Gridline Every to 10mm, for example, and the Subdivisions to 2, and hit OK. We see a change on the screen, and this will now be the new default.
Sometimes a particular weave size may be required, by, for example, fabric or carpet designers. We can also create non-printing ruler guides which tie in with our visible grid. To do this we first make our rulers visible via the View menu and Show Rulers (or press the Control key and the R key. We may also right-click on either horizontal or vertical ruler in order to check or to change these measurement units. If we wish to create a visible but non-printing horizontal or vertical guide, we first select the Selection tool (also known colloquially as the black arrow). Then we click and drag from the white space of a ruler onto the page itself. A small tooltip will appear showing the current position of the guide - we can either continue until the desired amount is reached, or we can highlight either the x or y coordinate and type in the required number, and hit the Enter/Return key to set the guide in place.
These guides are now locked by default but we can easily unlock them in order to make adjustments by going to the View menu, and choosing Guides and uncheck Lock Guides. To hide these guides we can press Control (Mac: Command) and the semi-colon key.
Tom Gillan has been training Illustrator to corporate clients in Sydney for seven years.Visit Design Workshop Sydney and get your Adobe Illustrator course .