Worbla's Finest Art ("regular" or "classic" Worbla) is essentially sawdust suspended in thermoplastic. One side (the "glue" side although both sides will become sticky if heated) is smoother than the other. The other side has a very faint pebbly texture to it. This can be eliminated in a variety of ways after which you can paint and decorate your piece as desired.
PROS: Worbla has no grain and thus can be stretched and formed into a variety of shapes. This makes it really good at forming curves such as breast plates, round shoulder pauldrons and so on.
CONS: The downside is that Worbla is not particularly strong on its own and, if stretched too far when heated, can tear. It is often backed or applied over EVA foam structures or reinforced with other thermoplastics such as Worbla Mesh or WonderFlex.