[NTG-context] Patterns in natural tables as background?

Hi, Is possible to put patterns as background in natural tables (bTABLE... eTABLE)? I'm thinking in striped background, or squared background or something more "complicated" as: http://fc05.deviantart.net/fs7/i/2005/249/c/c/Scanline___screentone_patterns... The problem I see is that we need some transparency if we want to put text as foreground and not sacrify the legibility of the text. Thanks a lot, Xan. PS: Please, CCme.