A process for producing paper webs having a pattern formed into the web is disclosed. The pattern is formed during formation of the web and is made by varying the basis weight of the web. The paper web is produced by depositing an aqueous suspension of fibers between two forming surfaces. One or both...http://www.google.es/patents/US7070678?utm_source=gb-gplus-sharePatente US7070678 - Paper webs having a watermark pattern
