Please forgive me for asking this question as I am new to this. Im ready to start doing some layout work and i wanted to know if there is a difference between the Pink foam from Lowe’s and Home Depot and the White foam made by Woodland Scenics. I know not to use regular white foam, but is there a diference in these two foams? I want to use this for a base as well as forming mountains, inclines and things.
use the pink,much cheaper.
I use pink foam because its cheaper and you don`t have to order it. 
Use the pink. (or blue) The WS white stuff looks like that bead board foam they use in packing. That stuff makes a real mess. The pink is about half the price.
For larger area’s go with the standard pink or blue foam. If you need smaller sizes and maybe odd ball depths then the WS will work fine. The WS is designed to work just like the pink/blue stuff it’s also the same material they use for their riser sets. I’ve used it, cut it with a knife, cut it with WS hot wire cutter, sanded it, painted it, etc. and it works great. WS foam is not the same as the normal white stuff that we have all heard about staying away from. Loathar’s comments are obviously from someone who has never used it or actually taken a good look at it. Just need to ask yourself why would WS put out something that wouldn’t work with their own products like the hot wire cutter.
Looked at it a few years ago at an LHS. (with my own two eyes) Even held it in my own two hands. Sure looked like bead board to me. Smaller beads than the insulation grade stuff.
Regardless of what I did or didn’t see… it’s still twice as expensive as the pink stuff which works great.
I use the white stuff as it’s easy to carve. The beads do show until I cover the mountains with many coats of Durham’s water putty and then it takes on a real nice stone texture. The water putty has gypsum in it so the mountain is about as fire-proof as a rock when done.
Full slide show with pictures is here:
http://home.mchsi.com/~ironmaster1963/wsb/html/view.cgi-photos.html-.html