I often make shirts for my husband, and my go to pattern is Simplicity 2741. The button placket is created by folding the front edge twice, and top stitching. I wanted to add piping, but since it's not a true placket (i.e. a separate piece of fabric attached to the shirt front), I had to get creative.
Well, it turns out that it's not all that difficult. All it takes is a modification of the way you fold the placket. I'll show you how. Click "Read more" to continue...
Normally, you would simply fold the front edge inward, twice as shown in the pattern instructions. We're just going to change the way we fold it.
The second fold will be pressed on the pattern fold line that is closest to the fabric edge.
The third fold will be pressed on the pattern fold line that is farthest from the fabric edge. Instead of folding inward as the pattern instructions show, fold this on outward -- the right sides of the fabric will be facing one another.
You can see that there will be a slight bit of the wrong side of the fabric showing on the outer edge. That's OK...it will be covered by the piping.
Now you can attach the piping. I pinned the piping at each end, and used a water soluble fabric glue to keep it in place between the pins.
Place one length of piping on the outer edge just underneath the top piece of the "placket" that has the scant 1/4" fold so that it sits between that top piece and the outer fold . The picture here shows the top piece of the folded placket pulled back in order to place the piping, so don't let that confuse you. The second picture shows how it looks once you've folded it back into place.
Place the second length of piping between the fold, and the shirt front at the inner fold.
I know the piping is a little hard to see in this picture because the piping color is so close to the shirt color, but you can see that just by modifying the fold of the placket, you can easily add it to a French placket shirt.