Method and arrangement for detection of a sychroniying mark being used in sychroniyed positioning of at least one essentiallz continuous material web

The invention relates to a method for detection of a synchronizing mark (6) being used in synchronized positioning of at least one essentially continuous material web (2), for manufacturing products (20) that comprise printed motifs (5; 5') or similar processed elements, which said material web (2) is intended to be divided into a nominal division length (LN) and comprises synchronizing marks (6) with a periodicity (Ls), which method comprises: detection of the respective synchronizing mark (6) for positioning the respective motif (5; 5') in a predetermined position on the respective product (20), which detection is carried out along a predetermined in the machine direction longitudinal section (24) of said material web (2). The invention is characterized in that it comprises: detection of said synchronizing mark (6) by distinguishing its colour or colour combination from colours or colour combinations in the rest of said section (24). The invention also relates to an arrangement for such detection, and an absorbent product.