These are .010″ Black Styrene Sheets by Evergreen Scale Models.

FEATURES: UV resistant polystyrene. Ideal for scratchbuilding…can be combined with wood, metal, and other plastics. Nontoxic and impervious to many chemicals, including water. Basic cutting, cementing, painting, weathering and wood grain techniques provided on package. Scale converstion chart provided on package. Made in the USA.

INCLUDES: (8) Sheets

TOOLS NEEDED: Stainless-Steel Scale Rule
Hobby Knife
Self-Healing Cutting Mat

SPECS: Sheet Size: 8″ x 21″ Thickness: .010″ (203mm x 533mm) (.25mm)