Abstract: An improved mixing scale, such as a paint mixing scale, includes a base which supports a scale pan in a substantially horizontal position. The scale pan supports a receiver container for holding the contents of that which is to be weighed. The mixing scale also includes a backing member which extends upwardly from the base and includes an output display near a top end of the member for presenting the measurement values produced by the scale. Proximate to the output display is a visual flow monitoring device, such as a reflector. Placement of the reflector proximate to the output display allows a user of the mixing scale to monitor the measurement value presentation and the flow of an additive being delivered into the receiver container simultaneously, or at the very least without requiring a physical shift in position by the user which might otherwise disrupt the delivery operation.