We now sell Sintra, a lightweight, easy to work with material that comes in a variety of colors including white, red, blue and yellow. Check the link at: Sintra Sales page
Sintra is easy to cut by scoring a line with a knife and then breaking it. Glue also works well bonding pieces of sintra together.
Note that we do not stock black sintra as black objects tend to absorb a lot of heat, so under 500W halogen lamps black sintra starts to become soft, this is less of a problem with brighter colors.