This tunic is the most economical use of fabric. It is based on rectangles and triangles and very easy to construct. As it happens, it's also fairly close to the method used in period for these garments. The sleeves and gores are the same fabric as the body of the tunic. You will need about 4 yards of fabric for a knee length tunic and 5 – 6 yards of fabric for full length tunic.
For the body of the garment, you will have a rectangle that reaches from your shoulders to the knee (or to the ground, depending what you want). Measure yourself at your widest point (chest or hips). Add 5”: 4” for comfort and 1” for seam allowance (1/2” on each side). This is the width of your body panel.
Have a friend measure the length for you; if you're doing it yourself, there's a good chance that you'll measure incorrectly as you try to see what the number is. Add 2” for a hem. You can cut two of these rectangles out of the fabric; or you can cut one long rectangle out of the fabric, if you don't want shoulder seams. If you're not making shoulder seams, mark the halfway point with a small snip in the seam allowance.
For the sleeves, which are also rectangles, take one end of your body rectangle and lay it across your shoulders along the top, so you can see where the edge will come over your upper arm.
Measure from that point to your wrist, and add seam allowance of ½” and hem allowance of 1”. This will be the length of your sleeve. Measure around your upper arm, and add 2" for a comfortable fit and ½” to each side for seam allowance.
If you wish to have a tapered sleeve, measure
around the broadest part of your hand as it would be for getting through a narrow
sleeve, not as it lies normally. Add the same amount of seam allowance, and
this will be the measurement for the wrist end of your sleeves
Now for the more complex part, the gores (triangles) that are added to the garment to form the skirt. These usually are set in starting at the waist, but also can be started higher on the body if you wish. These should be of the same fabric as the rest of the tunic.
Find the point on your body where you wish for the gores to start. Measure from there to your designated hemline, taking into account any extra length added for hem allowance. This measurement becomes the radius or side dimension of the triangles we are going to make to set in.
You will need 4 triangles, 1 each for each side of the front panel and 1 for each side of the back panel. The bottom width of each of the triangles should be about 5” for thigh or knee length tunic and about 10” for a full length tunic. Remember there will be 4 triangles. Gores can be left out of the thigh length tunic if you wish, but they are necessary for full length tunic so you can walk. One side of the triangle will be on the straight grain of the fabric and one edge will be on the bias. You will need to even out the length along the bias so that your triangles become circle segments. Do this by folding each once lengthwise, then cut across evenly from the shortest side.
Sew the shoulder seams, if applicable. Then cut the neck hole. It is easier to do this before the sleeves are added. Keyhole necklines are easy to do, and very accurate historically for a tunic. You can cut it out and edge it with bias tape or you can make a facing for the neck opening. The bias tape method is usually easier for beginners. If you use a neck facing, be sure to hand-stitch the edges so they lay flat inside the tunic.
Although humans vary in the shape of their necks, generally a squashed circle will work as a neckline.
The lines in this drawing show the center line of the body and the shoulder line in relation to the placement of the neck. Measure around your neck and adjust the squashed circle shape until you have one that looks like it will work for you.
To determine the depth of the slit in the front, take the difference between your neck measurement and your head measurement and divide it in half. This is the minimum amount of slit that you will need to get the opening over your head. You may make it longer if you like, of course. Cut it along the grain of the fabric in front.
If you're going to put trim around the neckline, it’s easier to do it before adding the sleeves. To fit flat trim or bias tape around the neckline, gently guide the trim around the neckline pinning as you go, you may need to add a few pleats at the shoulders. Sew on the edge or edges of your trim or bias tape.
Now that the neck is done, sew the sleeves to the body matching the center point of the upper sleeve with the shoulder. If you're going to put trim over this seam, add it now while the tunic is flat. Likewise, putting trim on the sleeve cuffs is easier at this time, don’t forget to leave room for a hem.
Sew the gores to the body with the bias edge of the gore matched to the straight grain of the body. You'll have one gore on each side of the body pieces.
You're almost done. Now all you need to do is
sew side seams from the wrist to the bottom using a ½” seam allowance, you will
need to pivot slightly as you go from the sleeve to the side seam. Now all you
need to do is hem the bottom and sleeves and add trim to any of the remaining
areas that you wish.
The Quicker Method
If you have a great deal of fabric, there is a
very quick way of making a tunic, which is to simply draw the outline on the
fabric as shown, using a shirt that is comfortable, over fabric that is folded
twice to produce both front, back and sides from one cutting. The neckline can
be made in the same way as described above. Be certain that the fullness at the
sides of the body is rounded so that it does not hang down unevenly.
The variety of patterns used during the Middle Ages is amazing. Diamonds (lozenges), circles, squares, rectangles, elaborate birds and beasts. Generally, if you are using commercial trim, anything that doesn't look too modern will work very well. Stay away from depictions of animals or flowers that look too realistic. There are a great many trims on the market, including basic grosgrain ribbon, which will do fine. If you're really inspired, you can do embroidery or beadwork! Buttons (shank type) were also known throughout our period for fastening and decoration.