Well, there's light up tubing you could use. www.tronguy.net
But you're aiming for something flatter, yes? Hrmmm...try browsing Jinyo's Count of Monte Cristo cosplay for ideas.
Here he gives some insight into what he used. Good luck!
"Don't worry about the world coming to an end today. It's already tommorow in Australia." -Charles Schultz
“If your knees aren't green by the end of the day, you ought to seriously re-examine your life.” -Calvin and Hobbes
In Progress: Alice (Pumpkin Scissors)