JTable does a fine job of laying out columns so they will fit into the table's containing viewport. However, if you would like your JTable's to allow the columns to be wide enough to necessitate horizontal scrolling, it can be tricky to figure out w/ the current JavaDocs. You can beg, plead, and threaten the JScrollPane all you want, but you won't get anywhere without calling JTable.setAutoResizeMode(JTable.AUTO_RESIZE_OFF). This should be spelled out somewhere in the JTable JavaDoc.