I'm trying to create a continuous scrolling graph. I'm reading in data, ploting it on a picture box, and scrolling the picture box as the data reaches the right edge. After all the data is taken, I want to be able to scroll the graph back to the beginning (and to points inbetween). Using BitBlt copies over the old lines. If I use 2 Picture Boxes, one inside the other, then the old lines get erased as they move past the edge of the other box. Is there a way to make a scrolling graph and preserve the early lines?