For over 50 years, Maya Blue has been an unsolved problem in the manufacture of ancient pigments. It can be reproduced with several procedures using palygorskite, indigo, and heat; however, we do not know how the Mayans made this pigment. Interpretation of ethnohistoric data allows us to deduce that Pre-Hispanic, and even Spanish Colonial, procedures for manufacturing indigo may produce Maya Blue if clay is added during the process. Ethnohistoric and archaeological evidence is presented to support this hypothesis, and following the proposed procedures, Maya Blue was reproduced in the laboratory. Microscopic examination and chemical microscopy were applied to the synthetic Maya Blue to characterize and compare it with original Mayan samples.