Use Holbein Acrylic Modeling Pastes to build up richly textured surface forms on canvas, board, or other painting substrates. They come in a number of specialized formulas. Like all Holbein art materials, these pastes are formulated to meet some of the most stringent quality standards in the industry. They are packaged in unique, freestanding poly bags — tough, durable, and better for the environment than standard rigid plastic containers.