Reinforcing the vents

My pencil skirt (which I have been making forever and has been the subject of several previous blog posts) has two front vents to enable you to walk.  On trying out the toile I worked out very quickly that these would need some industrial strength reinforcement.

Alice very kindly pointed me to this tutorial for Arrow Head tacks but I thought these would look a bit busy on my herringbone tweed. In the end I went for simple triangles sewn with a bit of bias binding at the back to strengthen them further.  I think they look quit neat!