You might be able to solve this by zooming in on the canvas, but unfortunately Paper can't currently do that. (A posting on the company's support forum indicates that that feature may be coming in a future update.) Without zoom--and unless you're gifted with a stylus or a finger--there's no way to create really detailed drawings.
There's also an unfortunate "bleeding across the page" effect when you return to notebook view: The canvas gets split up across the two "pages" of the notebook, which can make drawings look very strange. (You'd think there would be an option to draw on a single page in portrait, as there is in both Penultimate ( Macworld rated 3 out of 5 mice ) and Bamboo Paper, but there isn't.)
If you experiment with Paper, you'll probably wonder whether you need a stylus. I personally preferred using one instead of my finger, though I found that I had a difficult time using most non-nib styluses (Adonit's Jot Pro, Ten One's Pogo Sketch Pro). One exception was the Nomad Compose; the slanted brush worked best for me when sketching or using the watercolor brush.
Rewinding through time
Brushes and pretty books are nice, but the Paper feature that really caught my eye was Rewind, which uses a video shuttle metaphor for an undo gesture: By placing two fingers on the screen and turning to the left or right, you can undo/redo up to 20 lines.
This gesture doesn't always work, unfortunately, because "close page and return to the notebook" is also mapped as a two-finger gesture--a pinch. I finally found a way to do it by putting one finger down at a time, but it's a pain and ruins what's otherwise a fantastic bit of gesture innovation.
Speaking of undo, while the 20-line limit is understandable, I'd love to have a larger buffer. Even 20 lines aren't many when you're sketching with the pencil tool, especially if you want to experiment with different ways of coloring or outlining. (At the very least, I'd love to see an eraser with some opacity to it, or a way to duplicate sketches.)
When you're done with a drawing, Paper offers a few of the most popular options for sharing it--Tumblr, Facebook, Twitter, or email--but it neglects to provide the simplest one: Export to Camera Roll. If you want to do that, you need to snap a screenshot when the sketch is full-sized.
Paper's flaws are especially frustrating, because the app is otherwise so promising. There are parts of it I absolutely love. But until Paper gets a serious upgrade, I can't see it becoming my go-to sketching app.
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