I used foam sheets from Michaels. The larger costume for my 6 year old to 9 of the 12" x 18" sheets. He's 50" tall and weighs 50 lbs. I used a combination of a glue called Quick Grip (which held very well and stayed flexible but is messy and needs to dry overnight) and hot glue (for adding some of the detail work.) By the time I got to my daughter's costume I got a little impatient and used the hot glue for most of the glueing. I worked ok as long as you are quick with getting the pieces together quickly. But it does deform the foam a little and it is not flexible. You're also gonna need a couple of packages of white velcro strips (18" in length). And you'll need a length of 1" wide black elastic for the upper arm pieces - both for a strap around the arm and to attach them to the shoulder straps. I also used some to hold the thigh pieces up - one end hot glued to the thigh piece and the other has a velcro piece that attaches behind the belt.