If possible, using the angle 26.65 degrees results in much cleaner lines. It is a little thing I learned doing pixel art for games.
Is it trial & error or a mathematical background?
It comes down to the arrangement of pixels. Basically, you end up with something that is like: 2px over, 1px up. The inverse of that works as well. This results in a crisp line that avoids being anti-aliased.
Edit: This is a good visual explanation: http://gas13.ru/v3/tutorials/isometric_pixelart_tutorial_mathematics_of_isometrics.php Also, I guess that I was very slightly off. Looks like it should be closer to 26.565.
Here is the exact result :)
This one weird trick....
Joking aside this is super useful.
This works in Sketch, too! If anyone would like to check out my quick test you can download it here.