Hi @jtpausti ,

Looks like you use BMPOUT command to export drawing to BMP format.

You can use 2D Wireframe visual Style for exporting your drawing to BMP. In order to get rid of red lines you simply need to change color of the "L1D0" Layer from Red to "0,0,0" (HSL or RGB) True color:

See attached drawing where I changed color of this Layer.