Here are instructions for making a knight's sword for your outfit.
You will need:
Corrugated card (an old box will will work fine)
Cut out two blade shapes from card. Fold each in half to create a ridge down the side of the blades.
Cut a strip of card about 4 inches (10cm) longer than your blade. Arrange the two pieces of blade so the ridges point out and the strip of card runs through the middle, sticking out of the bottom. Wrap sticky tape around it to secure.
Wrap the blade with kitchen foil. You shouldnt need glue but if you want to use it to secure loose edges you can.
Cut two handles from card. Arrange them so they overlap the blade slightly and have the strip of card running in between them. Wrap tape around to secure them in place (you will need to use quite a lot of tape)
Jack with his sword, helmet and shield