A signal layer for an absorbent article provided to absorb menstrual fluid includes a pattern of capillary channels allowing capillary action such that discharged menstrual fluid that comes across one of the openings in the capillary channels enters into the capillary channels and is retained therein due to the capillary force. The color of the retained menstrual discharge dyes or colors the pattern for signaling purpose, and the pattern is directly or indirectly visible to an observer.