The vogue for architectural concrete has rendered white and colored concrete far more common today than previously. The problems inherent in white concrete are not so much in the design of the mix, but rather in the selection and placement of materials. Aggregates have an important bearing on the color of white concrete. If a white or clear aggregate such as quartz or marble is used, and especially the finer aggregates, a much purer and clearer white concrete will be achieved. If an aggregate other than white is used, the apparent color of the concrete surface will depend upon the depth of coloring of the aggregate and the amount of aggregate revealed in the concrete surface. When batching white concrete, more attention must be paid to keeping the proportions constant from batch to batch. Always use the same amount of cement to aggregate, and water to cement. The gradation of the aggregates must also be kept constant. The mixing time must be carefully timed and should be the same from batch to batch.