# Crossing lines

Sometimes it’s not possible in diagrams or charts, that a line goes over another one. To not let this crossing look like a real connection of the two lines, we can let the top line go over a gap in the bottom line. It would require to calculate the intersection of the lines.

However, there’s an easy way: draw the firsts line normally, then draw the top line with a bit whitespace around. Or the top line first thicker and white (or background color), then again thin and black (foreground color).

The probably easiest way in TikZ is: draw a “double” line (TikZ manual, 15.3.4 Graphic Parameters: Double Lines and Bordered Lines). Originally, it gives two parallel lines with space in-between filled by a color. But we want to get a single line. Solution: a double line in white, the gap between them filled in black. This results in a black line with white space around.

Many words, short and simple code example:

This way, `double distance` is the width of the actual black line, while `line width` stands for the white space on each side.

Use it such as:

It can look like:

Or: