Hi Emmanuel, I've worked out what the problem is!!

I have 2 printers, one A4, one A3. I set the paper size originally at A3 but when I changed printer I forgot to change the paper size to A3 in Page setup > Page format!! Hence it was scaling down from A3 to A4 by that weird amount.

This is only a trap for someone with 2 printers, probably a minority

Thanks for an excellent programme!!
Bob