Need Help in Modifying a DXF file

Hello everyone,

I'm a new user regarding CAD software and really never worked before with one. In this case what I want to do is to take a dxf file which was created by exporting data from another software in which i designed a printed circuit board.

The thing is that the 2 layers that were exported (1. copper wiring and 2. substrate background) are represented by the same color of lines and filling (white), and what i need to do is to change the filling color of the substrate layer to black so when I print it, it would appear like a negative image of my design.

I've tried in several ways to change the background or filling color for that layer but nothing seems to work, I would appreciate a step by step help if possible.

Thanks so much for it

Hello!
In case you use the version 2 of lc:

As you can see I created 2 objects


In order to change colors to the object click on modify and select the color that you prefere


Down here you can see  that I created a border


The idea is to create a solid fill hatch that cover the entire border area and to put it on bottom of the drawing, to do it click on hatches, create a hatch using the border as reference object, put then the hatch on the bottom of the drawing, look the picture down here to erase any doubt about how to do:


Now, if you click on print preview the trick is done! (here I did not change color to the objects/layers)



I hope I have been helpful,
bye bye!
Cla