Cool cool cool
>11 Aluminium lithographic offset printing plates
the. WHAT.
I actually laughed out loud when I got to that bit. It's a bit... mental... if I'm honest.. that whomever wrote this up included that. After reading through I can see this can just be substituted for general thin metal sheets which you can pick up from pretty much any hardware store. I assume it blows the $30 price point up a bit but that's far preferable than having that one, show-stoppingly esoteric essential item on the list.
This kind of thing is very cool weekend project fodder. I suspect it'll take me a bit longer than the couple of hours they reckon.