Deadlines and Reservations: For copy submission guidelines and deadlines and to reserve Advertising Ideas space, please go to the . Perspectives on History is now being produced in 4-colors. PLEASE NOTE: PDFs must have all fonts and images embedded within the document. All embedded images should also have a resolution of at least 300 dpi. If you are submitting a 4-color ad, please make sure that your PDF is saved as CMYK. If you are submitting a 2-color ad, please ensure that the 2 colors are black and process CMYK (C=88, M=70, Y=24, K=7) .