how to split a file into 2 equal parts or more for print?

[extentofmysin]

a simple question for simple ppl- how do I split a file
into 2 equal parts for print? its a single layer a2 image
within photoshop, but my printer can only print up to
a3, so i need to turn the top and bottom half into two
equal a3 images?

about as beginner a question as possible.. thanks

[Excruciating]

Well.
The a3 paper size is 297 × 420 mm. Simply click the 'Rectangular Marque Tool' and change the drop-menu in the top-file tray from 'normal' to 'fixed size' and enter 297 mm (remember to change px -> mm) as Width and 420 as height. Then simply copy the marqued selection selection by ctrl + x. Open a new canvas ctrl + n (The size will already be set to 297 x 420 mm because of the image in your clip-folder), hit enter and print!
Then do the same with the second piece of the image.

[tombothetominator]

^^ Good posting.