Boxing Corners

A boxed corner is a very useful sewing technique. It creates space in something, which is otherwise flat. For instance, there will be more room in your bag so you can keep more stuff. You can turn any corner into a boxed corner. You can do this in many ways – I will show you 2 most common methods of doing this.

A Basic Box Corner

I am using a light colored fabric and contrasting threads here so that you can see the steps clearly. The corners are sewn and it is shaped like a rectangle or square.

Simply follow these steps –

box corner

  1. Keep your fabric like this.
  2. Sew the bottom and side seams in a straight stitch. Pivot each corner. The seam allowance should be ½”.
  3. Keep the sewn side on the right side together. Pinch and pull apart your corners with both your hands. The fabric forms a small peak when you pull. A corner will point to the top. The seam lines will run down the front side’s middle and the back. Align the bottom seams and the sides. Make the seam allowances face opposite sides and place a pin to hold the matched seams.
  4. Mark the boxed corner’s depth with a marking pen and ruler. Here, my depth is 3”. Slide down the ruler from the peak until you reach where the triangle is at the right width (3”). Draw a horizontal line here.
  5. You can also measure from the seam’s corner vertically down along your seam line. Measure 1½” or half the width of the corner.
  6. Sew across the drawn line’s peak. Backstitch at the start and at the seam’s end.
  7. Trim the peak away to ¼” – ½” from the stitching line.
  8. Pull the corner apart at the seam line and you will see the corner taking shape.
  9. Turn over the fabric from the right and check the finished boxed corner.

how to box corners

Cut-Out Box Corner

Here’s the second way of creating your boxed corner. This approach is better when your fabric is heavier.

sewing box corners

  1. Place your fabric on a flat surface.
  2. Measure, mark, and cut equal sized squares from the corners.
  3. Sew the bottom and side seams separately. It should be a straight stitch.
  4. Now match the side and the adjacent or the bottom seam with the pin in place. Make the seam allowance face in opposite directions.
  5. Sew along the corner’s raw edges in a straight stitch. The seam allowance needs to be the same as the bottom and side seam allowances. Always backstitch at the end and the beginning of seam.

creating box corner

With a basic box corner, from one folded edge to the other at the peak’s base, the distance will be the depth of your corner. Here, I sewed 3” from fold to fold, across the peak, and thus I had a 3” box corner. Remember, the larger or deeper your box seam, the shorter will be your project. Also, you are going to have less depth if the box seam is shorter or smaller.