In today's Nerdy Sewing Tip, I'll be showing you how to quickly, simply, and painlessly create a perfect mitred corner, all on a sewing machine! If you've ever been frustrated by imperfect hand stitched mitred corners, or worried about the durability of mitred corners that aren't actually joined to each other along the diagonal, then look no further - this technique is both durable and flawless.
Fold and press your seam allowance in by 1/2", or 12mm. Apply this to all edges that will require a mitred corner.
Next, fold and press your seam allowance in by a further 3/4", or 20mm.
Open out the edges, keeping the original 1/2" fold in place.
Now fold the corner over diagonally so that you make a complete square with all the pressed folds lined up, as shown and highlighted in pink below. There's no need for you to draw out the square as we have, but if you feel like it might help guide you for the first couple of tries, go ahead!
Carefully press this diagonal fold.
Open out the corner - you should have a perfect diagonal press line skimming the corner of the innermost right-angle press line.
Now fold the corner back on itself, so that right sides are together. Make sure that all pressed fold lines match up, as well as the pressed and folded outer edge of your fabric.
To create the mitred corner, we're going to stitch along the press line that runs at a right-angle from the corner and down to the outer edge.
As there are two press lines that go from the corner to the outer edge, which could be easily confused, we've highlighted the one we're going to be stitching along below in pink:
Stitch along the press line, remembering to backstitch at the start and finish of your line of sewing.
Snip off the corner, about 2mm from the stitched line.
Now turn your corner out to the right side, use a point turner - or any long pokey thing (a knitting needle is ideal) to carefully push the corner out and give it a good press.
Repeat this process for all remaining corners, sit back and admire your work!