(NBBJ) - Two major suppliers of bottle-decoration services are significantly upgrading their production capacity as more vintners turn to screen printing as a luxurious-looking label alternative. To be sure, screen printing accounts for a tiny portion of labeling for wine bottles and historically has been for high-end brands. But Bergin Glass Impressions of Napa and Monvera Glass Décor of Richmond are busy keeping up with demand from wines retailing for less than $20 a bottle.