Lace insertion is the lace that is straight on both edges. If one side of the lace feels rougher than the other, this is the wrong side of the lace. I have used a contrasting color thread for the photos. Use a fine machine thread that matches the lace and a 60/8 size machine needle.
Starch and press the lace and fabric. Using a wash-away marker, mark the lace placement lines on the fabric. Set the sewing machine on straight stitch length of 2.0 and stitch close to the edge of the lace down both sides. I prefer to stitch from top to bottom each time to prevent the fabric and lace from distorting.
Turn the fabric to the wrong side, and carefully cut the fabric between the stitching lines, being careful not to cut the lace. Press the fabric away from the lace.
On the right side of the fabric, using a zigzag stitch of 2.0 width and 0.7 length, stitch over the previous stitching line. The stitch should "zig" into the lace and "zag" into the fabric.
On the wrong side of the fabric, using blunt scissors, trim away the excess fabric.