Inkscape: Copying an object, retaining transparency

I had the same problem. It seems the objects that have been copy-pasted have a white background. I found a way to put objects into another window without that background:

• save your first file (svg format)
• go to the other window
• import it (File -> Import)

This will import all objects that were in the first file, but you can delete the ones you don't need.

The underlying problem is that with current Inkscape packages for Mac OS X the pasted objects are indeed pasted as bitmap images (with a solid white background), instead of being pasted as vector copies of the original vector objects.

This is due to a known upstream conflict with the pasteboard syncing in X11/Xquartz: Copied vector objects are pasted as bitmap images, and no vector information (style, path) is available in other Inkscape commands either which expect vector data on the clipboard (e.g. paste style, paste size, 'Shape: from clipboard' in pencil/pen tools, 'Paste path' in the path effect editor, etc.)

Please adjust the X11 preferences for the pasteboard as described in the Inkscape FAQ: Copying and pasting in Inkscape creates pixellated images instead of copying the vector objects (and as seen in this screenshot). The changes will take effect immediately (no need to restart X11/XQuartz or Inkscape), but objects copied and pasted earlier will have to be redone.

In X11 preferences untick "Update Pasteboard when CLIPBOARD changes":

Alternatively, you can use the shortcut Ctrl-D to duplicate the selected object as this doesn't touch the clipboard.