This is the Pyramid Head costume I made for my brother. It took three days because of missing materials, drying paint, and hot glue injuries.
The helmet took the longest to make. It was made from cardboard, black and red spray paint, chalk, and mesh screen.
I had to add about two layers of cardboard to each side including the noise. The inside is layered with form for head support. The cracks were filled in by white chalk that you can find in all hardware stores. I needed to add alot of mesh screen to hide his face, but forgot to before the picture was taken.
Step 1: Creating the Triangles
Here are the measurements I used to make the helmet: (two panels for front and back)
Side #1: 39in
Side #2: 23.6in
The front panels are triangles with two angles at 36 degrees and about 108
other side: 27.5in
cut down middle to bend cardboard.
That is the back two triangles at 24 degrees at top and 78 degrees at bottom.