when I try to duplicate grease pencil layers using the "copy/paste" buttons I get a: "keyframe pasting not available for grease pencil mode" Any idea what I am doing wrong?
Yes, Ctrl+C gives that message. You should use the duplicate function, Shift + D.
if you want copy and paste all the layer, that is "imposible", the only way is to save the file with othen name and the import the gpencil with "append" or "link"
shift + F1.. but only you will have 1 layer at the same time
Duplicate the object the Grease Pencil layer is connected to. Rename the layer, and now add another layer and name it the same as the first object's layer. Now select the first object and then the one with two layers and press Ctrl+J to join the objects. You now have one mesh with two identical layers. Now you can go into Edit mode and press W > Remove Doubles.
In Blender 2.80:
- Select the grease pencil object first.
- Then, go to the object-data panel and then select the layer you want to duplicate.
- On the right side there will be button bellow '+' and '-' button. Click on it.
- Now, select the 'Duplicate Layer' to duplicate the layer.
See the image below for details.