Tutorial: Adding a traditional zip to cushion cover

The other day I showed you how to mitre the corner on these quilted cushion covers.  
Today I'll show you how to insert the traditional zip.

I am using a thrifting zip so it's too long.
Cut off to the size you require - making sure it's wide enough to get your cushion in.
Place pins where your zip will go.  Sew a basting stitch at your seam allowance between the pins and a normal stitch for the balance of seam at each end.
Finish edges and press open.

Take the right side of your zip and roll it along the pressed open seam.
Zip teeth should be aligned with the seam.
Pin to hold in place

Add your zip foot attachment to your machine and sew back and forth across the seam to match the width of your two vertical stitching lines along the zip.
Sew along one side of the zip edge and stop when you get close to the zipper pull (head).
Lift your fabric and gently undo the zipper pull past where you are sewing.
Continue to the end.
Change the zipper foot attachment to the other side and starting at the same end as before sew an even stitching line besides the zip. Stop when you again get close to the zipper pull.

Take your unpicker and carefully undo seam about 1-2 inches in length, just enough to pull back the zipper pull out of the way. Continue sewing and finish to match your other row of stitching.
Finish off by sewing back and forth across the other end - before the zipper stopper ends (they are usually two little metal pieces).
Press and continue making your cushion.