Things You'll Need
The medieval tunic in its simplest form has a rectangular body shape and either simple slits or slightly U-shaped openings for the neck and arms. Not all tunics have sleeves, and the sleeveless variety is by far easier to make — it's a no-sew costume.
Depending on the height and size of your child, a standard pillowcase may be big enough. If your child is taller, purchase a pillowcase made for a body pillow.
Choose a pillowcase for the tunic. Surprisingly, quite a bit of color was used in medieval clothing, particularly for festivals. If desired, choose a red, blue or purple pillowcase in a hue similar to what might be created from plant dye, or choose a muted earth tone.
Create a sleeveless tunic, suitable for use as a costume with a shirt under it. Fold the pillowcase lengthwise so that it forms a long, thin rectangle. Position the pillowcase so that the long, folded edge is facing away from you.
Cut armholes through both layers of the pillowcase, on the side opposite the fold, through the sewed together ends of the pillowcase. Make one cut through both layers starting about 2 inches in from the top corners and extending about 3 inches down the long side in a half "U" shape.
Unfold the pillowcase. Draw a neck opening in a half-oval shape on the sewed top edge of the pillowcase. Cut on the line through both layers of fabric to create the head opening.
Add a medieval themed design to the tunic using fabric paint or iron-on fabric. Use images such as a cross, a shield, stripes or a dragon.
To add sleeves, cut material from a second pillowcase. One end of the sleeve should be wide enough to fit the armhole you made, and the sleeve should taper slightly so that it's narrower at the wrist than at the shoulder.