imagearc() and imageline()

Hello, My question concerns the php function 'imageline' and 'imagearc'. I am = using them to create tables with rounded borders. I thouroughly = examined the specs for these methods and have come to the conclusion = that it is not possible to draw lines or arcs with a pixel width greater = than 1. Could you please tell me if there are other functions that = would allow me to draw arcs and lines and greater width. Thanks. Dan