I interfaced the centre front pieces with horsehair cut on the straight grain, with the side fronts interfaced with bias interfacing. Here’s a pic of the bound buttonholes. I’m pretty darn proud of them, I must say. I measure and re-measured and measured again, and they are as close to perfect as I could hope for. *grin*The facing is underlined with silk organza, and I used silk organza patches to face the buttonhole facings. And here’s the front facing, fell-stitched in place.