A muffle furnace is used to determine the ash content of paper or board. We follow TAPPI test methods T-211 (525 °C) and T-413 (900°C). A weighed sample is placed in a crucible and the sample is ashed at either 525°C or 900°C. The sample is removed from the muffle furnace and the weight of ash determined. If the coating formulation is known, the amount of ash present can be used to determine coat weight.