This ruler is 3mm width and with the special ruler foot from Westalee, I am able to use it with my domestic machine.
I'd never attempted a border treatment with this ruler and it went very smoothly - even for a first time! I thought I'd share a few pointers.
First I lightly marked the arc's on the border with a chalk marker.
I started marking at the corners. There is a line thru the center of the arc that is easy to line up along the border seams at the corners.
The arc's along the border needed slight adjustments to make it fit the length of the border so in a couple places when I marked to the top of an arc, I slightly moved the ruler then continued marking. This made the arc slightly longer without a noticeable difference.
***If your arc's fit the length of the border, you wouldn't need to mark them***