Useful angles for rotation and slopes

[Nominal Animal]

I've noticed that in my hobby designs, I can often get a nicer PCB layout if I rotate components.  However, aligning traces can then be annoying, especially because I like to use simple rectangular grids as guides for placing traces.  Picking rotation angles that match small integer ratio slopes makes it easy to use such a grid.  Since I don't like to memorize things, I created an infographic, a printable poster:

It's an SVG file, so it scales perfectly to any size.  Feel free to use any way you like.  The dark line is the exact slope, and the lighter line underneath is at the exact angle, so their convergence and divergence shows how much error there is between the slope and the angle.  Only the 45° angle is exact, all other angles are approximations (rounded to either the closest full degrees, or the closest tenth of a degree).

If you don't like the colors (grays), save the SVG file, and edit it in e.g. Inkscape, or any text editor: the colors are in hexadecimal, #RRGGBB, with 00=0% and FF=100%.  Opacity 0.0 is transparent, and 1.0 fully opaque.