The dyeing properties of silk from larvae reared on an artificial diet (AD-fibers) or mulberry leaves (ML-fibers) were evaluated in direct, acid and basic dyes. The AD-fibers absorbed more water vapor and liquid water and absorbed more direct dye. There were no differences with acid and basic dyes in equilibrium dyeing properties. The AD-fibers had a higher dyeing rate with acid dyes at 30°C. It was concluded that the AD-fibers may have a coarser structure. -- AATA