Caracalla Unknown

All half-tone books prior to 1890 are unusual and represent the earliest period of this form of printing in the United States. Many early examples have the half-tones printed on sheets, separate from the text, which is not the case here. The Half-tone caused a second revolution—in the type of paper used in books and magazines. Half-tones printed best on a smooth calendered paper that was glossy; since magazines prior to this used soft papers, it was necessary to change completely the paper used for the half-tone illustrations that rapidly became ubiquitous. Hanson