I wish to plot x-y scatter graphs to scale e.g. on a landscape A4 size page.
I need the y (vertical) axis to be exactly 99mm long and the x (horizontal)
axis to be exactly 240mm long.

As I cannot find rulers in Excel I insert the graph in Word and turn on the
rulers. I then stretch the “chart area” until the axes are the correct length.

This usually works. However, sometimes it does not work e.g. the y axis
might be around 20mm too long for no apparent reason but the x axis will be
correct. I also notice that if a text box overlaps an axis the length of the
axis changes.

Is there another way of achieving graphs to scale? Can the size of the “plot
area” be set precisely?

Can you also let me know if there is some sort of “show all characters”
command in Excel, which could be used to identify empty text boxes, which are
invisible?