Materials:
"Unbreakable" plastic comb; three single-edge razor blades inserted into teeth; wrapped with copper wire and shoelace.
Backstory:
During the 1980s, a modest stipend of $1.10 per day was deposited into each working prisoner's personal account. The comb and shoelace used here were available from the prison commissary at that time. By completing an order form, prisoners could make purchases and tailor a shiv to their own design specifications.