How do I paint an even stripe across a long long wall?

[GrendelsMum]

I'm going to have a big stripe of blackboard paint all the way across my kitchen wall (about 7m long, I think).

How do I get the lines perfectly even and level so DH doesn't sneer when he returns? Is there some kind of trick to doing it easily, and without having another adult to help mark the lines?

And any other tips on using blackboard paint?

Thanks as always!

[CMOTdibbler]

You need a laser level . It shoots a nice red line across the wall, and then you just pencil mark at intervals. After that, get the blue masking tape from Homebase, tape along the lines, then paint with a small roller (doesn't drip as much as a brush). Leave for an hour, then very carefully peel off.

You will need some help in the marking from someone reliable enough to hold still