Here are 6" x 4" sheets of white styrene for:
The uses are endless.
Use a heat gun to soften the styrene enough for bending. Be careful not to burn it or melt it.
The thinner it is, the more pliable it is.
Seven thickness sizes are available from thinnest to thickest:
Prices vary per thickness of material.
One 6" x 4" styrene sheet, by Evergreen