The material is unknown. It's likely not plastic, but something similar. However, it has a wood-grain pattern and a neutral color, and its simple, thin shape makes it a versatile coaster that complements any teacup. I only use these when guests come over, but there are some scratches and color irregularities visible. I hope someone who needs tea coasters can use these. Width: Approximately 12 cm Height: Approximately 2 cm