GDS II (also called "Stream" format) is used as an interchange between design systems and fabrication facilities. For information on reading and writing GDS, see Section 3-9-2 and Section 3-9-3, respectively. In GDS files, there are no names for each layer, just a pair of numbers (the layer number and type). It is important that Electric know how these values correspond with layers so that it can properly read and write GDS files. You can set the correspondences by using the GDS Map File... command (in menu File / Import) to read a GDS map file.
Figure 7.17

You can also use the GDS Preferences (in menu File / Preferences..., "I/O section, "GDS" tab) to edit the GDS numbers and control other aspects of GDS input and output.

Figure 7.27

Project Preferences

The left side of the dialog shows the Project Preferences which control the mapping of GDS layer numbers to Electric layers. The list on the left shows all of the Electric layers in the current technology. By clicking on a layer name, its GDS numbers are shown in the top-right and can be edited. In addition to GDS numbers to use for layout, there are also two other types of GDS numbers: pin (for exports) and text (for export names). To ignore a layer, clear the layer field (it is not sufficient to set it to zero...it must be blank).

These dialog elements apply to the export of GDS:

This dialog element applies to the import of GDS:

User Preferences

These dialog elements are available on the right side (the GDS User Preferences):