Fitting big squares of fabric to the angles and curves of a chair…Drape and Pin…That’s all there is to it. BUT, If you haven’t done this before, you know that is NOT all there is to it. That is why I have photographed some of the sticky and unfamiliar spots and explained how I do it.
Locate marked center front of chair seat at crease, center at top of backrest and center back (shown). I marked mine with a large head pin so I can feel it when the chair is covered with upholstery fabric. Match center pressed line on the cover with the marked centers on the chair. My chair makes that easy with its center seamlines.
Drape COVER over chair from front to back. Smooth the fabric on the chair seat so the centers of fabric and seat match. Fold out the 2 inches at the seat crease before draping the cover up and over the backrest.
Refer to previously market seat edge [indicated by yellow arrow], backrest edge [indicated by the other yellow arrow], marked seat side edge [indicated by blue arrow], and center pleat fold line [indicated by black arrow]
On the pleat foldline, slash to a scant distance to the outside of the seat edge mark. Then finish the raw edge with zig-zag, pinking, or serging. Finishing will allow you to wash the cover later on without it raveling to ruin.
Fold the cover in half on the pleat foldline. Pin in place. Seat edge and backrest edge will match by default. Stitch on that line about 1″ centered on the seat edge mark. The green arrow points to that mark. The yellow line illustrates the stitching.