One roller printing machine could print as much yardage as twenty hand-block printers. The early machines could print only one color, but designs were often enhanced with additional colors added by block printing or by penciling (hand-painting). As roller printing became more sophisticated, printers experimented with new techniques, such as gradually shading the colors on the roller in order to achieve a “rainbow” effect. These color gradations—sometimes also called “ombre” or “fondu” prints—were particularly popular in the second quarter of the 19th century.