Colour bars: Narrow strips on the back edge of the sheet in four-colour process printing showing densities or evenness of ink across a sheet.是什么意思_Colour bars: Narrow strips on the back edge of the sheet in four-colour process printing showing densities or evenness of ink across a sheet.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句