A lot of new sewists put off making their first bag because it seems to be a really scary concept. There are zips and 3D items and it feels a world away from the comfort zone. But believe me, it isn’t actually too difficult and you use the same set of skills over and over again.

Most of the time, the enquiries that I get about bag making woes and difficulties centre around zippers and getting them right, This time though, I want to focus on boxing the corners of a bag. What is it? Why do we do it? And, above all, is it difficult?

Boxing corners is the procedure of cutting a square out of a lower corner (I know sounds a bit scary but bear with me) and then pinching the seams together and re-sewing.

It is not hard to do at all and the reason that we do it is to add instant volume to a bag without having to fuss around adding side panels and gussets. These have their place too as do darts but nothing will turn your beloved creation from a flat piece to a real life bag faster than boxing the corners.

You cannot box the corners on a pattern unless the pattern is written for it because the corners must be allowed for in the measurements and the designer has to calculate this accurately. So unfortunately this is not one of those things where you can easily adapt an existing pattern. Winging it means that you will upset everything in the pattern including the placement of pockets, straps and any other motifs.

Still, most good patterns have these features and the great news is that they are especially good for beginners! So let’s get started!

You do not need anything at all apart from your pattern, a ruler and some sharp scissors to box the corner on your bag. I will be referencing my latest Etsy pattern, the Toulouse French Market Bag for this but the procedure is the same for any other patterns so you can transfer the skills easily to any pattern that you have at home.

The time for boxing corners comes when you have sewn the bag front to the back. You will have a situation like this…

It looks a bit boring because you are looking at it from the wrong side and there are some extra seams in the picture above. These are basting seams from attaching the bag outer to the foam interfacing. That is one reason why we do not box from the seams – there are too many of them sometimes and it gets confusing. Ignore them for now.

Now the first bit is scary because it feels as though there is no going back. You have to cut a corner from the bag. To begin with, the patterns will tell you what to do. For example, the Toulouse pattern tells you to cut a 2 1/2″ square. Firstly, you draw it in….

Use your water soluble marker or whatever you are comfortable with and make sure that the squares are the same for both corners. Measure twice and cut once! There is a reason why that is such great advice and never assume that you can just eyeball it! Draw yourself a line to follow.

When you measure the cutout, measure from the edge of the bag NOT the seam.

So when you have measured and checked, cut the corner out…

The first thing that you will find is that the seam wants to come undone because you have essentially cut through the stitches. You can combat this by re sewing the seams near the cutout. With more experience, you can also anticipate where the cutouts will be going and shorten the seam length in that area. This helps to stop the stitches unravelling.

Now the next bit is where you have two seams – the one on the bottom of the bag and the one on the side. Pinch them together and pin or clip…

There are a couple of things to know here. Number one, the more precisely you bring the seams together, the better the outside of your bag will look and the best way to achieve precision is to open the seams out. You can actually see if they are precise or not then. The bulky but necessary foam interfacing means that the bag will put up a bit of a fight but clips help to keep the seam flat.

Okay so the next job is to sew the new seam and create the boxed base. Do this by sewing along and back stitching at the beginning and end of the seam…

That is actually all there is to it! Check your seam from the outside and the corner should look something like this….

If the seams are off, it doesn’t look great so be prepared to unpick (don’t worry, it happens to all of us at some point because fabric shifts thanks to physics). If it keeps happening, hand baste the seam right along. That solves all sorts of issues actually.

Repeat this for the other corner and also for the lining.  Basically, whatever you do for the outer, do for the lining too. Sometimes the lining cutouts will be a different size but this is rare. Usually it is exactly the same and your pattern will tell you what to do.

So there you have it! This is an essential skill and a lot of the better looking bags have boxed corners. As I said, it is easier than some of the other options and it is quick.

Thank you so much for stopping by! If there is anything that you would like me to feature in more detail to help you with your bag making, please let me know if the comments section. Don’t forget to subscribe by email so that you know what we are up to over here.

Hugs

Debbie xx