Hi Mark,
Welcome to the forum and it's good to hear you are enjoying the quality of Qimage printing.
All I've been doing is giving him a .Tiff file but I'm sure I could be doing a lot better using qimage. Any suggestions would be greatly appreciated!
QU has a feature for preparing images for out-sourced printing, it's called "Print to File" from the File menu.
You can read about it in the Help, Contents, Learn by example "Example 25a: "Preparing Pages of Prints to be Sent to an [Online] Printing Service"
You will need to know what is the preferred resolution required by the printing outfit and the profile they would like you to use. Some may even let you have their printer profile to embed in the image.
The advantage of using the PTF feature is that QU smart print sharpening can be used - one of the reasons why QU produces excellent prints.
(EDIT) I should have mentioned the other reason for high quality prints from QU, that is the interpolation method used - "FUSION" is world class and beats anything other software offers.
There are others on the forum that use print-to-file for out-sourced printing regularly (I don't) so they may be able to offer specific advice, otherwise ask again if required and we can probably still help you.
One other point, QU has special canvas printing features: canvas wrap borders and a canvas shrinkage allowance setting.
Terry