Foam core or foam board consists of an expanded polystyrene foam core with each face covered in paper, with the whole thing usually being black or white. It is usually recommended when needing a rigid and lightweight material to be attached or suspended without much support like a tacked-up sign or prop. It can be laser cut, however the thicker the material gets the more concave the cut face will be as the foam will melt back at a rate much higher than the paper faces. If you are looking to use a thicker piece of foam core we usually recommend cutting a few layers of the same design from thinner sheets and laminating them together in order to get more detail in the final pieces. It is also a good idea to avoid intricate details like thin/sharp corners as these will at best melt back to become rounded or will just catch on fire which is not great. The backside will have some degree of scorching depending on the thickness.