Setting a gore into slit fabric

Are you trying to sew your own Charles de Blois-style pourpoint and are not sure how to set a gore into a slit? You will need this skill for attaching the front gores and underarm gores, which are part of a faithful reproduction of the sleeve. Inserting a triangle into a slit in fabric can be tricky, especially if the point of the triangle is sharp. Aside from the pourpoint mentioned above, many other surviving garments from the Middle Ages employ this tailoring technique.

It is found in multiple 14th- and 15th-century kirtles from Greenland and Scandinavia (Bocksten Man, Kragelund, Skjoldehamn, Moselund, and the Herjolfsnes 38, 39, and 41 to name some) as well as hoods found in Herjolfsnes, Greenland, London, England, and Dordrecht, The Netherlands. It is also found on the pourpoint of Charles de Blois, from Angiers, France, the St. Louis shirt also from France, Fernando de la Cerda’s saya and pellote in Spain, and the Moy Bog dress in Ireland. Some extant hosen employ a similar tailoring technique in attaching the foot to the legging. It is worth noting that not all gores set into slits are pointy: some are gently curved at the top of the slit, others have multiple prongs sewn into the slit. If you want to explore 14th-century tailoring techniques, this is a good one to master.

Below, you will find a picture-aided tutorial showing a step-by-step process for inserting a gore into slit fabric.

I found it was easier to learn this tailoring concept when first practiced by hand, rather than by machine. If you get the gist by hand and are comfortable using a sewing machine, feel free to proceed to the machine, if that is your preference.

I used two contrasting fabrics in the pictures below to better illustrate what each piece does in relation to the other; not because gores should contrast with the main fabric. I don’t recommend sewing contrasting gores into your historical clothing without some documentation for doing so.


Start with a swatch of fabric with a slit cut into it and a triangular gore as seen below:

Practice fabric pieces

Practice fabric pieces


With the slit fabric front-side-up, turn the gore back-side-up and line up one of its edges with one side of the slit. (It doesn’t matter which side you start with.) The picture below has been marked to show you how the gore should be placed on the slit fabric:

  • black lines to indicate where the slit should be located under the yellow gore,
  • a red dot showing where the gore stitching should begin, and
  • a red dashed line to show how the stitch line should progress.
Placement of the gore on the slit

Placement of the gore on the slit


To begin sewing, insert the needle through the back side of the slit fabric, keeping it very close to the top of the slit as seen below:

Inserting the needle at top of slit

Inserting the needle at top of slit


Sew one side of the gore to the edge of the slit. The stitching should remain a steady 1/2″ or 5/8″ (whichever is your usual preference) from the edge on the gore side. On the slit fabric side, the stitching should begin very close to the top of the slit and gradually move outward until it is 1/2″ or 5/8″ away from the slit at its bottom. The next two pictures show what the stitching should look like on each side. First you can see that the stitching remains 1/2″ away from the gore’s edge:

First side sewn

First side sewn


Second, you can see that the stitching starts very close to the slit fabric’s edge and gradually moves further away until it is 1/2″ away from the edge at the bottom. To understand why this happens, click here:

How stitching looks from back

How stitching looks from back


Next, begin to pull the gore open so that the second side can be matched up to the other side of the slit:

Beginning to pull gore fabric through the slit

Beginning to pull gore fabric through the slit


Carefully pull all of the seam allowance of the gore into sight on the back side of the slit fabric. Line up the remaining gore edge to the remaining slit edge. Note that they will not line up evenly until the bottom of the slit, as already demonstrated above:

Fabric pulled through the slit

Fabric pulled through the slit


To begin sewing, put your needle through the back side of the slit fabric, very close to the top of the slit, just as you did with the first side you sewed. It is ok to have both knots right next to each other:

Sewing the second side

Sewing the second side


Stitch the second side of the gore to the second side of the slit. Notice that on the slit fabric, the stitching starts very close to the edge of the fabric, gradually moving further away until it is fully 1/2″ or 5/8″ from the edge by the time it reaches the bottom:

Second side sewn

Second side sewn


When finished, iron the gore flat over the seam allowances of the slit fabric. You may need to snip a small slit in the slit fabric’s seam allowance at the point of the gore to relieve tension there. Notice that on this side, the stitching is always 1/2″ or 5/8″ from the edge of the gore:

The gore ironed flat

The gore ironed flat


Turn the swatch over to the front side, and you will see a neatly inserted gore:

Neatly-set gore

Neatly-set gore


To finish the seam allowance, roll the gore’s seam allowances under, encasing the slit fabric’s seam allowance, using a whip stitch or running stitch to secure it:

Seam allowances finished

Seam allowances finished


The front of the finished gore looks like this:

Completely finished gore

Completely finished gore

Leave a Reply

  1. Thanks so much for that..
    I have made 3 garments now with underarm gores, flying by the seat of my pants, and have survived it, and they look good, but have been using a machine… (fie on me!!!)… it’s been tricky.
    Do you have a tutorial for a really good method for inserting underarm gores, or different methods you prefer?
    I’ve spent quite a bit of time picking out the seam allowances after stitching the wrong parts too far when go to stitch the next corner.. .. I think you’ll know what I mean.. I can laugh now!!!
    Thanks so much for your amazing site.
    Lizzi

    • Hi there, I’m so sorry for taking so long to respond! I think that inserting under-arm gores or gussets might work differently, depending on the shape you’re using for the gore or gusset, and whether or not you’re setting it into seamed fabric or slit fabric. I don’t have a tutorial for that, alas. Thank you for the compliment about my site!

  2. My first Pennsic I made myself 7 or 8 of the rectangle/triangle T-tunic and the gores in the slits drove me batty!!! I got them done but hated the way they looked (nobody else noticed, but they looked “glumpy” to me). This seems similar to the way I tried to do it, but even easier. I can’t wait to try this on my next gore/slit project.

    Thanks!

  3. Your site came up first on my google search for How To Sew Gores, and I am so glad! Your instructions are very clear and simple and I now no longer fear the gore! Thank you so much! Now on to gore some jumpers…. :~)
    Shawn

  4. Glad they helped! I had no idea when I wrote this little tutorial how welcome it would be. :^)

  5. Pingback: Machine Sewing an Inset Gore | By My Measure

    • Glad it helped! It’s a concept problem for most — once you accept that at the very tip there isn’t much room for seam allowance, it starts to make sense.

  6. Thank you so much for the outstanding tutorial! I just sewed gussets into a slit, as opposed to into a seam, and figured out how to do it by trial and error instead of researching it first. Turns out that my method ended up being the same as what you outlined here. It’s good to know that I was doing it right! I wrote about it on my sewing blog if you are interested in checking it out: http://www.fabricoftime.blogspot.com I will be sure to point out your tutorial on my blog.

  7. Wow! that went in just right! even after I had to add and extra 3″ piece to make up for the pattern piece shrinking when I turned my back! OK measure twice cut once! Now I want to go back and redo all the other gores I have set in in the last year. Thank you for the clear help

    • Glad it helped, Gail! I had to once figure it out with trial and error myself and then I realized a lot of people still had not and I could save some frustration by laying it out pretty simply. So far, so good.