This is a great, low profile splint for Radial Nerve Palsy. Patients tend to love it because of its light weight and use friendly design. I prefer to use Orfit Classic 2mm for this one, but you can use any 1.6mm or 2mm thick thermoplastic. You want the thermoplastic to have a little bit of give, which gives it a semi-dynamic feel. I would not go any thicker than 2mm unless it is a very large hand. I find the Orfit Classic being a good option as you can use its characteristics of it being sticky when it is warm. This makes the splint conform very well with a very good fit.
I did a presentation a while ago that has step by step photos on how to make the Pulvertaft Splint, you can find it here.