How to Sew a Gore into a Fabric Slit
by Tasha Dandelion Kelly
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. Below, you will find a picture-aided tutorial showing a step-by-step process for inserting a gore into slit fabric.
I find it is easier to learn this tailoring concept when first practicing 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:
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:

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:
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:
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:
Next, begin to pull the gore open so that the second side can be matched up to the other side of 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:
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:
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:
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:
Turn the swatch over to the front side, and you will see a neatly inserted 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:

The front of the finished gore looks like this:

This tailoring method 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 methods, this is a good one to master.
For further reading:
Burnham, Dorothy K. Cut My Cote. Toronto: Royal Ontario
Museum, 1973, 1997.
Carlson, I. Marc. Some Clothing of the Middle Ages: Historical Clothing from
Archaeological Finds. Accessed May 2, 2009. http://www.personal.utulsa.edu/~marc-carlson/cloth/bockhome.html.
Crowfoot, Elisabeth; Frances Pritchard and Kay Staniland. Textiles and Clothing,
c.1150–c.1450. (Medieval Finds from Excavations in London: 4) London:
HMSO, 1992 and Boydell Press, 2001.
Hald, Margrethe. Ancient Danish Textiles from Bogs and Burials. tr. Jean Olsen. Copenhagen: National Museum of Denmark, 1980.
Harmand, Adrien. Jeanne d'Arc: Ses costumes, son armure: Essai de reconstitution. Paris: Librairie Ernest Leroux, 1929.
Jones, Heather Rose. "Another Look at Saint Louis's Shirt" Tournaments Illuminated. Winter 2002, 22–23.
Nockert, Margareta. Bockstenmannen, Och Hans Dräkt. Halmstad och Varberg: Stiftelsen Hallands länsmuseer, 1985.
Østergård, Else, Woven into the Earth, Textiles from Norse Greenland, Aarhus University Press, Aarhus, Denmark, 2004
Copyright © 2004–2009 Tasha Kelly McGann. The author of this work retains full copyright for this material. Permission is granted to make and distribute verbatim copies of this document for non-commercial private research purposes provided the author's name, the copyright notice, and this permission notice are preserved on all copies. Linking to this site is allowed without permission. Questions and comments can be directed to tasha@cottesimple.com