Applying unreduced indigo dye directly to fabric, usually using large, engraved copper plates
What to look for:
Finely detailed designs; a design repeat of 24 to 36 inches; lighter shades of blue
China Blue was the second method developed (after Pencil Blue) to apply indigo directly onto fabric. In this method, unreduced indigo was printed directly on the cloth and the chemical ferrous sulfate was used to reduce and fix the dye. Printers often used the China Blue method in combination with large, finely engraved copper plates to make monochromatic pictorial prints, like the toile de jouy you see at right and below. This method rarely achieved the deep blues of other methods.
The name likely evolved from the resemblance of these prints to Chinese blue-and-white porcelain that gained popularity in Europe during the 17th century after trade with Asian countries became widespread.