How to draw a model with ruler scale that is 3d printed

I’m creating a model using sketchup web. It will be 3d printed and will have a ruler scale on it.
For the scale lines, would prefer the lines be recessed. I’ve tried using the line tool. I draw a line on the model, but it doesn’t print. Does the line have to raised or recessed for it to print. How do I do that.
I’ve searched for it, but can’t find anything. The link below is all I see. But it doesn’t go into detail how the scales are made.

Place scale measurements on a model - SketchUp - SketchUp Community

Please don’t double post. I answered your question in the other thread.