Instantly recognisable, Swiss cheese makes an ideal choice for a humorous fancy dress costume. The costume can be made fairly easily from stiff sheets of foam rubber, cut to shape with a retractable-blade knife. Remember to be careful when using the knife, as its blade can be extremely sharp.
Cut the foam rubber into shape. Use the retractable-blade knife to cut the foam rubber slabs into two rectangles of 2 feet by 3 feet, one rectangle of 2 feet by 2.5 feet and a triangle with a base of 2.5 feet and two sides of 3 feet.
Cut arm and head holes into the foam rubber. Lay one of the longer rectangles on top of the other long rectangle. These will be the sides of the cheese costume. Using the knife, cut an armhole through both rectangles about 10 inches in from one end. In the triangle, which will be the top of the cheese costume, cut a hole about 10 inches from the triangle's base, in line with the point of the triangle. Make sure this hole is large enough to fit your head through. The remaining rectangle -- measuring 2 feet by 2.5 feet -- will be the back of the costume.
Prime the foam rubber with spackle. This can be painted over the foam rubber with a regular paintbrush and then left to dry. This will prime the foam and ensure that it has a smooth surface for painting over.
Spray the foam with yellow paint. When the spackle has dried, spray paint the foam with water-soluble yellow paint. It may be necessary to use multiple coats to get an even finish.
Attach the foam shapes together using the superglue. Attach the two longer rectangles together, end on end. You must make sure that the armholes are closest to the unjoined ends of the foam sheets. Then attach the two ends of the shorter rectangle to the two unattached ends of the longer rectangles, creating an open triangular prism. Lay the triangular foam sheet on top of the structure and make sure the head hole and both armholes are in line, and then attach with the superglue. It is advisable to reinforce the joints by piercing the foam and threading cable ties through the holes. The cable ties will keep the foam rubber structure strong. Keep the costume looking neat by hiding the cable tie fasteners on the inside of the cheese costume. To get into the costume, lower it down over your head so that your head is in the head hole and your arms are in the armholes, and the apex of the triangle is in front of you.
Using a paintbrush, paint circular "holes" on the outside of the cheese costume. This gives the impression of a Swiss cheese with lots of holes in it. Paint the visible parts of the cable ties yellow to camouflage them.