Standardization of information was an effect of printing; since it allowed exact reproduction of information in a way that manuscript copying did not. This is evident in the contrast between the travel logs of Marco Polo and those of Christopher Columbus. After his return from China in 1295, a century and a half before printing, Polo's narrative was copied in about 150 different manuscripts, with so many differences that we're not sure which version is authentic. In contrast, there is only one version of Christopher Columbus's letters about the exploration of the Caribbean in the 1490s, since they were fixed in printed form and widely distributed at the time they were written. So the certainty of accuracy was a way that printing was an improvement over the old oral-manuscript culture.