i'm new to flying RC planes, saw dave's plans and it caught my interest. bought the plans and finnaly found a store to purchase depron from (shipping is intense from US). now i need to find a better place to fly.
You can use cheaper foam if you want... but we found the Depron from Europe works best, in terms of rigidity.
In the US... FFF foam is common, but in EU, I believe Depron is the common foam over there.
Also, welcome to the hobby!