I want to create a picture made up of 20 photos- 5 across, 4 down- then upload it onto Photobox or similar and order it as a mousemat.
I haven't taken the 20 photos yet but tried making a mock-up using any old snaps, on Photoshop (a v basic version). I managed to get it looking as I wanted but couldn't upload it- Photobox just said "problem with photo".
Is Photoshop the right software for what I want? Is there something easier (um, Word? I don't have much). Is there a particular size and format a picture needs to be to be uploaded? It should be easy, shouldn't it? I'm such a technodunce.