The ability to adjust the size of a canvas is not yet available in Draw so, yes, you'd have to send to the desktop then resize.
Okay, this has been a known issue since at least January. Is there any idea how long before the export ability for mobile is fixed?
This feature is definitely being worked upon.
Appreciate your patience.
I'm sorry for taking so long to respond. To expand on what Sheena's said... The reason all answers regarding this seem insufficient is because, this is not a bug. The behavior is intentional.
That is, when saving a drawing as as an image, Draw, for historical reasons related to its origin as Adobe Ideas, will export at 2048x1536 with the artwork being cropped to what’s visible in screen (similar to what you're referring to as a screenshot). So, when someone wants a tighter or looser crop, the zoom percentage must be changed prior to saving.
One other thing to consider with Draw... any strokes outside of the primary canvas area are actually considered part of the composition so any save will show that gray background because there are marks on it (this is not true for Sketch).
All of that said, the product team is considering a change to the way images are saved. That change could come as soon as the summer update (it's more likely that it would be in the fall).
In the meantime, to export a drawing at its highest resolution, and with a canvas size the dimensions of what's listed, art can be exported either a PSD or a PDF.
I hope this helps.
Except I tried the PDF export and the resolution was 1200x1200 rather than 2100. That may only be for PDF as I would hope PSD would keep enough of the original data (I use a tablet almost exclusively; my PC can't run Photoshop due to being Linux).
Oh. So your actually saving as a PDF then just exporting the image from the PDF? I know you don't have Photoshop, but do you have any way to open the PDF and export the art as an SVG?
Saving as a PDF is the only way I can get a usable image file out of it that respects the selected border (even if it still doesn't respect the resolution). It's a workaround I found mentioned in another forum. Keyword: Workaround.
As for getting an SVG out of the PDF, I don't have a good way of doing that. All I want to do is go from one app to another on my iPad so I can upload directly to my DevART, Instagram, and Behance profiles. If I have to bring a PC into the mix, then the app isn't convenient for me if I'm on the go, traveling, or otherwise unable to get to a PC. Using CC to export a PDF as an image file to use in another app wouldn't even be a problem if it worked at the desired resolution of 2100x2100.
You can say "The behavior is intentional" all you like, but giving me an option to select a resolution and then ignoring it is bad design. If the app was being repurposed, then putting in features that don't work is dishonest. I never heard of Draw before Draw. I never heard of Ideas and never used it, so I went into draw with the expectation that it would perform as it describes itself, but if it can't export an image at the resolution I select, then I have a right to complain and get an answer that isn't a dismissal. Yes, it's being worked on and may be patched later, but this has been four months and you're bloody Adobe, not some startup that needs Kickstarter to pay its staff.