animation - Onion skin wont show unless I draw on the frame, and only shows the lines directly around it from previous frames and won't lower onion skin's opacity - Blender Stack
Grease pencil onion skin not showing in draw mode 2.81 but works fine in 2.80 - Blender Stack Exchange
Grease pencil onion skin not showing in draw mode 2.81 but works fine in 2.80 - Blender Stack Exchange
animation - Onion skin isn't showing but I checked everything I was supposed to. How do I fix this? - Blender Stack Exchange
Onion skin is shown after rendering animation - Tutorials, Tips and Tricks - Blender Artists Community
2D animation style like Darling in the Franxx using Blender (free animation software) – Page 3 – 3DCineTV
Blender 2.73 – a new storyboard workflow » Cosmos Laundromat - The Gooseberry Open Movie Project