I prepare the images in Photoshop and edit them on the desired sizes, these may vary (A4, A3, 22, 3 x 32, 7 cm, 18x36cm, 18x68cm...).
Resolution is constant at 360 dpi.
The images are not but trimmed to a paper size to the desired final size for printing.
Please clarify the above, and then I am certain we have the solution.Specifically what size paper are you using, and specifically what size prints are you ordering?
In other words, if you use A3 paper, what size print do you wish to have on it?
Or... are you saying that the print you are making on a 9600 Epson is on a roll of paper and you want the print to be A3 size, or 11.7 inches x 16.5 inches, which is the dimension of A3 on the US.
Terry does the metric calculations, but either way we need to know your need.
In case 2) you would tell Qimage to make a print FIT TO PAGE after setting the page size to A3 as Terry showed in his previous post. Then Print!
In case 1) You Set the page size to the print size you want, and after making the page size in Print to File, again, Fit To Page. Print
Lat us know...