The layer file is a text type file (ASCII) with the extension .lay that can be edited with the help of the command ProfCfg - Files Tab.

In this file the layers allocated for the program are saved. The layers saved in this file are automatically created in the drawing when the program is loaded.

The layers from this file can be allocated for:
• PLT_POINTS: points;
• LONG_PLAN: longitudinal and cross profiles (polylines allocated and markings);
• TRAN_PLAN: cross profiles in plane (labels);
• TRAN_SECT: polylines allocated for cross profiles (generally unprintable layer);
• PRF_TAB: profile tables;
• PRF_CODES: texts with the drawn point codes and the point codes from the tabel (generally unprintable layer);
• PRF_PAGE: pages;
• OTHER: other layers that can be introduced by the user.

For each layer it can be specified if it is to be used or not in the drawing, the color, if it is opened or closed and if it will be printed or not. A layer for which the option not to be used is chosen will not be created in the drawing.

The layers defined in this file are saved inside the .dwg file in order to be reloaded at the next use of the drawing.