This guest post was written by Lavender Marsh for Threadsquare.
This is far from a groundbreaking, world changing technique. But I thought I’d share anyway, simply because lapped zips always seemed fidgety to me when I first started sewing. The trouble always occurred in the left seam allowance. It just never permitted enough room for topstitching the lap, or not enough to my liking. This was especially problematic with heavier fabrics, where I like to use as much width of the zip tape as possible so that the lap will lay flat. When I would stitch my preferred distance to the left of the seam, I’d barely catch the underlying seam allowance. Here’s my simple fix:
When cutting out pattern pieces, switch from 5/8” SA to 1” at beginning of zip placket. Trim off excess at garment’s right side – laps are generally on the left, so that is where you’ll need the extra 3/8”. Finish edges of seam allowances (my demo pieces are simply pinked).
Stitch seam RS together, B to T to bottom of placket, back tack, then machine baste the placket. Clip basting stitches to assist in removal later, about 1” intervals.
Turn garment right side up, top toward you. Fold SA of right side under 1/2”, leaving 1/8” exposed. Press or finger press.
Pin to right zip tape, with top of tape hanging off edge (good thing you bought a longer than called-for zip! So much easier than working around the bulky stop.) and bottom stop at bottom of placket.
Baste, if necessary, or simply stitch from B to T, with zip foot to left, needle close to folded edge. Pull thread to back & tie off.
Lay left side of garment back over zip tape. There is now plenty of SA on left side to stitch garment to zip.
Align center seam to the stitch lines you just made (notice these stitches are a continuation of the seamline). Pin and hand baste across bottom, then 1/2” from seamline.
With zip foot to right, start with needle at seamline. Hand crank over zip, pivot and stitch to top, just outside of basting.
Bring threads to back, tie off, remove basting. Et voila! You could also hand-pick for a couture touch. The extra bit of zip will be cut off when the waistband or facing is sewn.
Read more about Lavender’s sewing adventures on her blog, Threadsquare.