The method comprises the steps of: feeding at least a first ply (V1) of web material around an embossing roller (3) of an embossing unit; embossing the first ply, generating thereon embossing protuberances through protrusions (3P) of said embossing roller; applying to at least a first ply of web material at least two glues of different colors along adjacent longitudinal portions spaced from one another by a longitudinal band without glue; joining at least a second ply (V2) to the first ply by gluing; and producing at least on the first ply (V1) a printed pattern on the band without glue.