I'm not able to print big but I was interested in the new canvas wrap  border feature in Qimage and wondered about the technique for wrapping material onto a block mount.
So, I had a go using 3 thickness's of 5mm foam board and Epson Photo paper (80gm).
I used spray adhesive to stick the foam board together and made it 125 x 175 mm. I also adhesive sprayed the front face of the foam block secure the print and the wrapped the print around to the back with "envelope" folds and secured with double sided tape. The back was tidied up by sticking a rectangle of thin card to it.
The mirror border was set to 20mm and extra wrapping allowance created with a 15mm no. 2 border. I printed with  crop guide lines.
To enable accurate alignment of the block, I marked out the back of the print to the block size and pre-folded along those lines.
The result is shown below.
I'd be very interested to hear from the pro's on the forum detail of what extra allowances they make for the wrapping and the technique used to deal with the corners.
I'd thought I might make a few more as small gifts or one's with a Christmas greeting and a suitable seasonal image. I may use Ilford Smooth Fine Art paper, it has a nice texture.
Terry

Hi Terry,

I've spent some time folding paper around corners. I think, for the sort of item you are making, and as you are using glue, I would cut the corners, so that the edge of the paper was exactly on the corner edge, but overlapping  the other piece folded around from the other edge. I am not posting images, since if folk get a slab of foamex/chipboard/aluminium/whatever, and a few sheets of paper, they can try it for themselves, and may come up with a better idea.

Paper tends to crease easily, and although I have managed to fold it, such that the diagonal fold is underneath, I'm not sure if the result is reliable (in as much as I can always get it right) or even if it looks better cf the diagonal fold on the outside, as you have shown. Of course, if you're doing more than one or two, then scoring/pre-folding would be the way to go.

I think, instead of the white back sheet (although you could write your greetings, or similar there) I would try a blurred mirror image of the front.

Nice idea.

Best wishes,

Ray

Thanks guys for the suggestions for dealing with the corners.
I've got a Christmas greeting print ready so when I've assembled the foam block, I'll try the various suggestions with scrap paper.
I'll be good practice for wrapping those pressy's neatly. 
Terry.