My technique is also to screen copy the map and paste it into an image editor, crop out the rubbish and stitch together a number of squares to make up a basemap. It takes a lot of these to fill a 1 kilometer square and you need to ensure that you are getting the same scale each time if you are unable to complete the square in a single session.
For this reason, I always use the left-hand button [Select a Point] when zooming in. Its slow getting there but you will get a consistency of zoom that you won't get with the other button.