HELP!!!!

Jack and I have been reading this book called Nat Fantastic, which he loves.
Nat turns into a superhero at bedtime when his Mum leaves the room.
Great story by the way. And this is the HELP part of the post... Jack asked me yesterday - "Mum can you make me some of pyjamas just like that?" Hmmmm So where will i find silver fabric suitable for pj's???????? I have had my thinking cap on thinking of all the different ways to do this - Dye??? Won't give the same sheen as a nice silver fabric, If i can find silver fabric suitable for sleeping in then i could print stars on the fabric.... Possibly....
Then I also have to find something similar to the pants....... So hence my HELP moment - any ideas out there?????