I tend to give answers on the basis that the people reading know enough about programming to understand them.
Also, PLEASE edit your post to add info, don't post an 'answer' that is another question.
I have to guess what you're doing ,given that you never post any code.
Here[
^] - the MarginBounds gives you the bounds of the printable area. So, you centre your cheque inside that area, and it will be centered on the page.