There are many bodges for making sewn corners but a true mitre is a delight! Instructions can be tricky so I have a video guide on my Instagram and Facebook pages :)
Here are my written notes for making a napkin with mitre corners, with a finished hemmed border of approx 3/4”.
Because the unfinished border is about 1” on each side then for a 7” x 7” napkin, cut a 9” x 9” square of fabric.
You’ll need to make yourself a template and for this an old postcard will work just fine. Along the top edge, somewhere near the middle, cut out a rectangle that’s 1.5” across (so measure 1.5” on the top edge of your card) by 1” deep (being the depth you are going to cut out of the card).
Take your square napkin and turn it so that the pointy bits are top, bottom and sides and the right side of the fabric faces up. Bring the top point down to the bottom point (right sides together) so that you now have a triangle with a folded edge at the top, two points at the side and a point facing you. You’ll be looking at the wrong side of the fabric now.
Starting with the right point; place your template over it so that the top right of the cut out rectangle meets the very point of your fabric. It’s as if the point of the fabric is pointing to the top right hand corner of your cut out rectangle. Looking back towards the fabric triangle, the top of your postcard template should lie along the top fold of the triangle.
Draw a pencil line on your fabric down the inner left edge of your cut out rectangle, to give you a 1” line that starts at the top fold. If you find it easier you can then pin the marked line. Using a small stitch setting, machine stitch down this 1” line, starting at the folded top. Do a few reverse stitches at the 1” mark so that the stitching won’t come undone.
Trim off the corner; start with scissors parallel to the stitching and then angle slightly towards where you started stitching as this will help you get a neat point when you turn the corner to the right side. Now move your fabric as necessary to repeat this process on the other three corners.
Turn the corners so that the right side is facing you and using a turning gadget or a pencil, gently push out the points of the corners. A napkin with puffy mitre corners will form! Pop your finger under each corner to make sure the corner seam is lying flat. Press the corners, making sure that you press them into right angles (see tips below).
When you have all four corners done you can turn the raw edge of the hem under and press. Stitch close to the turned edge to finished the hem.
~ I recommend you practice with some square scraps to become familiar with the process.
~ If you cut a square of fabric the approximate size of your finished napkin it makes a great ironing board guide for pressing your corners into right angles with straight edges.
~ If you want to change the size of the border then practice with your own template using different measurements of similar proportions. Measure your square before and after doing the mitre corners so you know what seam allowances to make for cutting your fabric.
Happy Napkin making!