Question
How can I change the size of the grid-area when I print my Ganttchart?
Answer
When you print you call Gantt.PrintPage and this method has a a rectangle for the margins and a GridWidth, these parameters define the grid size.
System.Void PrintPage ( System.Drawing.Graphics G, System.Drawing.Rectangle Margins, System.Int32 aGridWidth, System.Int32 aDateScalerHeight, System.Boolean& HasMorePages)