From davidcapello on May 24, 2012 08:53:05

There are some internal settings that can be set in aseprite.ini (or ~/.asepriterc) for onionskin which are really useful and should be configurable via UI (in the Animation Editor). With these settings you can see other frames when the onionskin is enabled. Here are the default values:

[Onionskin]
Enabled = no
PrevFrames = 1
NextFrames = 0
OpacityBase = 128
OpacityStep = 32

E.g. If you want to see the previous frame and the next frame, you could configure it as:

[Onionskin]
Enabled = yes
PrevFrames = 1
NextFrames = 1
OpacityBase = 128
OpacityStep = 32

Original issue: http://code.google.com/p/aseprite/issues/detail?id=110