[Scribus] Q: Adding image with transparency

[D. R. Evans]

I am slowly (very slowly :-) ) making some progress at understanding Scribus.

Here is the issue that currently has me stumped.

1. My lowest layer is coloured a uniform grey colour.
2. In GIMP, I have created an image with opacity 15%, and exported it to PNG.
3. Back in Scribus, I created a new layer (call it gimpimage)
4. On the gimpimage layer, I created an image frame of the right size,
and imported the image.

But the result doesn't seem to show any of the background layer
through the gimpimage layer (the background seems to be white rather
than the grey colour of the lowest layer).

I've looked to see if I can find a setting to tell an entire layer not
to be completely opaque, but there doesn't seem to be any such
setting.

So I am very confused about the right way to layer a semi-transparent
image on top of a background. Any advice/help (especially if couched
in simple terms) would be most helpful.

Oh, and this may be a completely different issue, but if I Cut the
GIMP image and tried to Paste it directly into Scribus, nothing seemed
to happen. It seems like I had to actually save the GIMP image as a
PNG image and then do a Get Picture in Scribus. Is that expected
behaviour? I don't really mind (it's safer anyway to have a backup
file of the image), but it just surprised me that I couldn't simply
cut-and-paste the image from GIMP to Scribus.